I will review the current status of indirect dark matter searches, and discuss possible future directions.
In this talk, I will describe the status and plans for PandaX dark matter search from Jinping Undeground Lab in China.
We discuss the paradigm of dark matter from a hidden sector, and observational implications for colliders and direct detection experiments.
The rotation curves of spiral galaxies exhibit a diversity that has
been difficult to understand in the cold dark matter (CDM) paradigm.
In this talk, I will show that the self-interacting dark matter (SIDM)
model provides excellent fits to the rotation curves of a sample of
galaxies with asymptotic velocities in the 25 to 300 km/s range that
exemplify the full range of diversity. We only...
High-energy gamma rays of interstellar origin are produced by the interaction of cosmic-ray (CR) particles with the diffuse gas and radiation fields in the Galaxy. The main features of this emission are well-understood and are reproduced by existing CR propagation models employing 2D Galactocentric cylindrically symmetrical geometry. However, the high-quality data from instruments like the...
The next Galactic supernova (SN) will probably occur while current or next generation neutrino experiments are online. It is crucial to have correct understanding of the basic characteristics of the expected neutrino signals. The nominal expectation of the duration of the neutrino signal is ~ 10 s; this expectation guided both theoretical and experimental effort. We simulate SN neutrino...
SPIDER is a balloon-borne telescope designed to characterize the linear polarization of the cosmic microwave background at degree angular scales, and in particular to place constraints on the $B$-mode angular power spectrum arising from primordial gravitational waves. For the inaugural flight in January 2015, SPIDER observed approximately 12% of the sky with nearly 2000 detectors at...
For more than a decade VERITAS, an imaging atmospheric-Cherenkov telescope array, has been probing the Northern very-high-energy (VHE; >100 GeV) gamma-ray sky. Located in Southern Arizona, VERITAS consists of four 12-m diameter reflectors and is one of the worlds most sensitive detectors of gamma rays between 85-GeV to 30-TeV. Over 50 galactic and extra-galactic sources have been detected at...
I will present a new upper limit on CMB circular polarization from the 2015 flight of SPIDER, a balloon-borne telescope designed to search for B-mode linear polarization from cosmic inflation. Although the level of circular polarization in the CMB is predicted to be very small, experimental limits provide a valuable test of the underlying models. By exploiting the non-zero circular-to-linear...
For more than a decade the MAGIC Collaboration is delivering outstanding results in the field of very high energy gamma-ray physics.
The two 17m telescope system is one of the best performing instruments in its class, especially at low energies,
crucial for observations of e.g. high redshift sources, pulsars and GRBs. This talk will discuss recent key results from Galactic and extragalactic...
Supernova neutrinos can experience “fast” self-induced flavor conversions almost immediately above the core, with important implications for the explosion mechanism and nucleosynthesis. Very recently, a novel method has been proposed to investigate these phenomena, in terms of the dispersion relation for the complex frequency and wave number (ω, k) of disturbances in the mean field of the...
The propagation of charged cosmic rays through the Galactic environment influences all aspects of the observation at Earth. Energy spectrum, composition and anisotropy are changed due to deflections in magnetic fields and interactions with the interstellar medium. Today the transport is simulated with different simulation methods either based on the solution of a transport equation...
While the LCDM model has been wildly successful at explaining structure on large scales, it fails to do so on small scales---dark matter halos of scales comparable to that of galaxy clusters and smaller are more cored and less numerous than LCDM predicts. One potential solution challenges the canonical assumption that dark matter is collisionless and instead assumes that it is...
Cosmic rays propagate in the Milky Way and interact
with the interstellar medium and magnetic fields. These interactions produce emissions that span the electromagnetic spectrum and are an invaluable tool for
understanding the intensities and spectra of cosmic rays in different
regions of the Milky Way. Hence observations of these emissions complement information from cosmic ray...
I introduce the idea of using neutrinos as probes for measuring the size of the solar core. I review previous work showing that neutrinos from galactic supernovae, detected in water Cherenkov experiments such as Super Kamiokande, can be used to locate their sources. Using these ideas I discuss my recent work in Phys.Rev.Lett. 117 (2016) 211101 on the prospects for measuring the size of the...
The South Pole Telescope is a 10-meter diameter telescope located at the NSF Amundsen-Scott South Pole Station in Antarctica, designed for high-precision measurements of the temperature anisotropy and polarization properties of the cosmic microwave background. The third-generation camera on the telescope, SPT-3G, was deployed in the 2016-2017 austral summer season and represents a significant...
It is widely believed that Galactic Cosmic Rays (CR) are accelerated in Supernova Remnants (SNRs) through the process of diffusive shock acceleration. In this scenario, particles should be accelerated up to energies around 1 PeV (the so-called 'Knee') and emit gamma rays. To test this hypothesis, precise measurements of the gamma-ray spectra of young SNRs at TeV energies are needed. Among the...
The odd-parity (B-mode) polarization anisotropy of the Cosmic Microwave Background (CMB) provides a unique window into the history and contents of the universe. At sub-degree scales this polarization is primarily created by the gravitational lensing of the CMB due to intervening large scale structure while at degree scales B-mode polarization can indicate the presence of primordial...
Galactic supernovae are rare, just a few per century, so it is important to be prepared. If we are, then the long-baseline detector DUNE could detect thousands of events, compared to the tens from SN 1987A. An important question is backgrounds from muon-induced spallation reactions. We simulate particle energy-loss processes in liquid argon, and compare relevant isotope yields with those in...
A general mechanism for thermal production of dark matter (DM) via 3-to-2 scatterings, or other higher-order interactions, allows for sub-GeV dark matter and strong self-interactions that meet existing constraints but have the potential to explain mysteries with cold DM and structure formation. In such models, so-called Strongly Interacting Massive Particles (SIMPs), a correct thermal average...
The Alpha Magnetic Spectrometer (AMS), on the International Space Station (ISS) since May 2011, has acquired the largest number of particles ever measured in space by a single experiment, performing the most precise measurement of galactic cosmic rays (GCR) to-date. The detailed time variation of multiple particle species fluxes measured in the first years of operations, during the ascending...
TeV observations of gamma-ray sources are very important probes of cosmic-ray accelerators, as leptonic and hadronic spectra differ in this energy range. The High Altitude Water Cherenkov (HAWC) Observatory, located in Puebla, Mexico, is capable of detecting air showers initiated by gamma rays in the multi-TeV energy range. The upper end of this range is previously unexplored. The detector...
The Sun shadow can be measured with the IceCube detector and varies in depth corresponding to the magnetic field. Hence, we are given a possibility to understand cosmic ray propagation in the magnetic field of the Sun, for which a sufficiently good modelling is necessary. We investigate the field with its temporal deviations in strength and orientation. In times of low solar activity, the...
The thermal relic density of dark matter is conventionally set by two-body annihilations. We point out that in many simple models, 3→2 annihilations can play an important role in determining the relic density over a broad range of model parameters. This occurs when the two-body annihilation is kinematically forbidden, but the 3→2 process is allowed; we call this scenario "Not-Forbidden Dark...
I will describe a novel method to measure the absolute orientation of the polarization plane of the CMB with arcsecond accuracy, that will enable unprecedented measurements for cosmology and fundamental physics. Existing and planned CMB polarization instruments looking for primordial B-mode signals need an independent, experimental method for systematics control on the absolute polarization...
Super-Kamiokande (SK), the world's largest underground water Cherenkov detector, observes about 2 muons a second passing through it at a depth of 1 km. A fraction of these muons shower, and sometimes create radioactive isotopes (spallation). Those isotopes live anywhere from microseconds to several seconds, forming a dominant background to neutrino searches above 6 MeV and below 20 MeV....
NOvA is a long-baseline neutrino oscillation experiment with the
primary goals of discovering CP violation in the neutrino sector,
determining the neutrino mass hierarchy and constraining the mixing
angle $\theta_{23}$. NOvA also has a rich program of cosmic ray and
astrophysical measurements. We will set competitive limits on the
flux of magnetic monopoles as well as for neutrinos...
The existence of dark matter is one of the few solid hints for physics beyond the standard model. If dark matter has indeed particle nature, then direct detection via scattering on atomic nuclei is one of the most promising discovery channels. In order to connect this nonrelativistic process with astrophysical and collider searches, as well as UV model building, a consistent setup of effective...
The Sun and Moon produce deep deficits in the nearly isotropic flux
of TeV cosmic rays measured at Earth. Observations of these
cosmic-ray deficits, or "shadows," can provide unique measurements
of the solar and Galactic environment. For example, the displacement
of the shadow of the Moon in the geomagnetic field allows for charge
discrimination of high-energy Galactic cosmic...
We present results of a search for galactic PeV gamma rays with the IceCube observatory, presently the most sensitive facility for PeV gamma-ray sources in the Southern Hemisphere. This includes a search for point sources over IceCube’s field of view, as well as tests for correlations with TeV sources detected by H.E.S.S. and neutrino events from IceCube’s high energy starting event sample,...
Increasingly precise maps of the polarization of the CMB are a unique and powerful tool for understanding new physics, including inflation, the superluminal expansion of the universe during the first moments after the Big Bang. I will discuss constraints on inflation, set using the BICEP series of experiments at the South Pole (BICEP2, The Keck Array, and BICEP3). I will then discuss...
HETDEX (Hobby-Eberly Telescope Dark Energy eXperiment) is a galaxy survey targeting Lyman-alpha emitters (LAEs) at high redshifts (1.9<z<3.5). Starting from late 2017, the survey will observe about a million LAEs over ~400 sq. degrees, which corresponds to ~10Gpc^3 in volume. The main science goal of HETDEX is to measure the angular diameter distance and the Hubble expansion rate at high...
We study simplified models of flavoured dark matter in the framework of Dark Minimal Flavour Violation. In this setup the coupling of the dark matter flavour triplet to SM quark triplets constitutes the only new source of flavour and CP violation. The parameter space of the model is restricted by LHC searches with missing energy final states, by neutral meson mixing data, by the observed dark...
The Alpha Magnetic Spectrometer (AMS) is a multi-purpose magnetic spectrometer measuring cosmic rays up to TeV energies on the International Space Station (ISS) since 2011. Its precision, large acceptance and ability to identify particle types over a wide energy range during its long duration mission in Space make it unique in astro-particle physics. To date AMS has collected over 100 billion...
An important source of background in direct searches for low-mass dark matter particles are the energy deposits by small-angle scattering of environmental γ rays. We report detailed measurements of low-energy spectra from Compton scattering of γ rays in the bulk silicon of a charge-coupled device (CCD). Electron recoils produced by γ rays from 57Co and 241Am radioactive sources are measured...
Supernova remnants (SNRs) have been studied at GeV energies using the Fermi Large Area Telescope (LAT) for nearly a decade. The detection of the pion bump in four SNRs demonstrates that these are sources of cosmic ray protons. However, the detailed physics of particle acceleration (or re-acceleration) and diffusion remain undetermined. To determine the Galactic cosmic ray contribution from...
Many dark matter interaction types lead to annihilation processes which suffer from $p$-wave suppression or helicity suppression, rendering them sub-dominant to unsuppressed $s$-wave processes. We demonstrate that the natural inclusion of dark initial state radiation can open an unsuppressed $s$-wave annihilation channel, and thus provide the dominant dark matter annihilation process for...
The Light Dark Matter eXperiment (LDMX) proposes a high-statistics search for low-
mass dark matter at a new experimental facility, Dark Sector Experiments at LCLS-II
(DASEL), at SLAC. LDMX employs the missing momentum technique, where electrons
scattering in a thin target can produce dark matter via “dark bremsstrahlung” that are
not observed in the detector. To identify these rare signal...
Precision measurements by AMS of the antiproton flux and the antiproton-to-proton flux ratio in primary cosmic rays in the absolute rigidity range from 1 to 450 GV are presented based on $3.49 \times 10^5$ antiproton events and $2.42 \times 10^9$ proton events. At $~20$ GV the antiproton-to-proton flux ratio reaches a maximum. Unexpectedly, above 60 GV the antiproton spectral index is...
The next frontiers in cosmic microwave background (CMB) science include a detailed mapping of the CMB polarization field, with goals of detecting the inflationary B-mode signal and constructing high-fidelity maps of the matter distribution via CMB lensing reconstruction, as well as a first detection of CMB spectral distortions. At these levels of precision (~nK), Galactic and extragalactic...
We consider the indirect detection signals for models containing a fermionic DM candidate, a dark gauge boson, and a dark Higgs field. Compared with a model containing only a dark matter candidate and vector mediator, the addition of the scalar provides a mass generation mechanism for the dark sector particles which, in some cases, is required in order to avoid unitarity violation at high...
Charge-coupled devices (CCDs) are excellent particle detectors with the ability to probe a wide range of low-mass dark matter candidates. Initially developed for use in astronomy, CCDs have low per-pixel noise and excellent spatial resolution, giving them unique background discrimination and low (<100eV) energy thresholds. I will present the status of the DAMIC100 experiment, an ongoing direct...
Inflation generically predicts a background of primordial gravitational waves, which generate a primordial B-mode component in the polarization of the cosmic microwave background (CMB). The measurement of such a B-mode signature would lend significant support to the paradigm of inflation and be important for development of quantum gravity theories. Observed B modes also contain a component...
The origin of the Galactic Center Gamma-Ray excess still remains unclear. Astrophysical interpretations have been proposed, but these explanations require either a significant degree of tuning or a large population of millisecond pulsars that have a very different population than that observed in globular clusters or near the Milky Way. If the dark matter annihilation interpretation is...
An anomalous, apparently diffuse, gamma-ray signal not readily attributable to known Galactic sources has been found in Fermi space telescope data covering the central ~10 degrees of the Galaxy. This "Galactic Center Gamma-Ray Excess" (GCE) signal has a spectral peak at ~2 GeV and reaches its maximum intensity at the Galactic Centre (GC) from where it falls off as a radial power law...
We present the latest measurement of the combined electron and positron flux in cosmic rays based on the analysis of all the AMS data collected during more than 5 years of operations. The multiple redundant identification of electrons and positrons, and the match of energy measured by the 17 radiation lengths calorimeter and the momentum measured by the tracker in the magnetic field enable us...
SuperCDMS (Cryogenic Dark Matter Search) has been one of the leading direct dark matter search experiments using low-temperature semiconductor detectors. The recoil energy induced by dark matter scattering inside the detector is measured using phonon (lattice vibration) and ionization signals. CDMSlite (low-ionization threshold experiment) within SuperCDMS Soudan has the best dark...
Several groups have demonstrated the existence of an excess in the gamma-ray emission around the Galactic Center (GC) with respect to the predictions from a variety of Galactic Interstellar Emission Models (GIEMs) and point source catalogs. The origin of this excess, peaked at a few GeV, is still under debate. A possible interpretation is that it comes from a population of unresolved...
Recent direct measurements of cosmic-ray (CR) light nuclei (protons, helium, and lithium) by AMS-02 have shown that the flux of each element has an unexpected hard component above $\sim 300~{\rm GeV}$, and that the spectral indices of those components are almost the same. This implies that there are some primary sources that produce CR lithium nuclei, which have been believed to be produced...
The Lyman-alpha forest provides a powerful probe of cosmic structure at z = 2-4, with physics that is relatively straightforward. I will discuss current constraints on dark energy from baryon acoustic oscillation measurements in the 3-d Lya forest and on neutrino masses from the 1-d Lya forest power spectrum, with measurements coming from the Baryon Oscillation Spectrosopic Survey (BOSS). I...
The MiniBooNE experiment at Fermilab performed the first dedicated search for accelerator proton beam produced dark matter. By steering the 8 GeV beam into an iron beam dump, the neutrino production from charged meson decay was suppressed while the photon production from neutral mesons remained unchanged. According to hidden-sector vector portal models, the Standard Model photons kinetically...
I will present results from the completed Sloan Digital Sky Survey (SDSS)-III Baryon Oscillation Spectroscopic Survey (BOSS) and initial results from the SDSS-IV extended BOSS (eBOSS). These experiments have obtained spectroscopic redshifts for nearly 2 million galaxies and quasars, allowing the creation of 3 dimensional maps spanning most of the history of the Universe. In addition to other...
Analysis of anisotropies in the arrival directions of galactic protons, electrons and positrons has been performed by AMS on the International Space Station. An absolute anisotropy measurement has been performed with protons, electrons and positrons. These, together with the results of the anisotropy analysis of the electron to proton, positron to proton, and the positron to electron ratios...
Scintillating bubble chambers are demonstrated to have clean separation between electron recoils and nuclear recoils down to a thermodynamic “Seitz” threshold of 2 keV with a prototype liquid xenon chamber developed at Northwestern University, as the former only produce scintillation light while the later produce both scintillation light and bubble nucleation. This clean separation is expected...
A clear excess at ~2 GeV, known as the Galactic-Center Excess (GCE), has been detected in the Galactic Bulge region by the Fermi telescope. In addition, the Galactic Bulge is characterised by the annihilation of positrons resulting in a 511 keV line. Both signals look morphologically similar, but so far a detailed comparison has been lacking from the literature. We model the GCE using the new...
We model galaxy-galaxy lensing and clustering into nonlinear scales with a suite of N-body simulations, and we project significantly tighter cosmological parameter constraints possible within the ΛCDM parameter space and a HOD galaxy biasing model by using small scales. To include possible assembly bias effects, we introduce a two-halo environmental density dependence parameter into our model...
In this talk, I will present the application of Calogero's Variable Phase method for the determination of Sommerfeld Enhancement factors relevant for dark matter cross section calculations. In contrast to directly solving the radial Schrodinger equation, the evaluation using the Variable Phase Method offers a rapid and stable evaluation, even for multichannel systems. Time permitting, I will...
We report the measurements of the fluxes of elementary particles: electrons, positrons, protons, and antiprotons, in the cosmic rays by the AMS experiment. The measured spectra show distinctive features that cannot be explained by ordinary cosmic ray models. In particular, in spite of the different production and propagation properties of protons, antiprotons and positrons, the...
The MAJORANA DEMONSTRATOR is an experiment constructed to search for neutrinoless double-beta decays in germanium-76 and to demonstrate the feasibility to deploy a large-scale experiment in a phased and modular fashion. It consists of two modular arrays of natural and 76Ge-enriched germanium detectors totalling 44.1 kg, located at the 4850' level of the Sanford Underground Research Facility in...
Cosmological perturbation theory is a powerful tool to model observations of large-scale structure in the weakly non-linear regime. However, even at next-to-leading order, it results in computationally expensive mode-coupling integrals. In this talk, I will focus on the physics of our extremely efficient algorithm, FAST-PT. I will show how the algorithm can be applied to calculate 1-loop power...
We will review the status of the observations of cosmic neutrinos and the model-independent constraints on the properties of the sources where they originate. We will emphasize the multimessenger relations connecting neutrino, gamma ray, and cosmic-ray observations and conclude that neutrinos are ubiquitous in the nonthermal universe suggesting a more significant role than previously...
Searches for ultra-high energy neutrinos ($E>10^{17}$ eV) probe the
nature of the highest energy universe in a unique way and test our understanding
of particle physics at energies much greater than those achievable at particle
colliders. I will discuss the range of strategies used to search for the highest energy neutrinos via radio emission from neutrino-induced showers, and the current...
I will review some of the open questions in high-energy neutrino astronomy raised by the observations of IceCube in concert with cosmic ray and gamma-ray observatories, and how they can be addressed through a new generation of neutirno observatories.
The elusive nature of dark matter calls for new ideas. An old but largely overlooked possibility is compact dark matter—perhaps primordial black holes—with masses comparable to the masses of stars. Null microlensing searches rule out fairly robustly masses below ten solar masses. Constraints to higher masses are, however, a bit trickier but have been the subject of considerable recent...
Cosmological observations represent a powerful tool to constrain neutrino physics, complementary to laboratory experiments. In particular, observations of the cosmic microwave background (CMB) have the potential to constrain the properties of relic neutrinos, as well as of additional light relic particles in the Universe. I will present current constraints on neutrino properties, focusing on...
Several starburst galaxies have been observed in the GeV and TeV bands; in this
regime, gamma-rays are mainly produced by cosmic-ray interactions with the interstellar medium ($p_{\rm cr}p_{\rm ism} \to \pi^{0} \to \gamma\gamma$). Furthermore, the dense environments of starbursts may act as proton "calorimeters" where collisions dominate losses, so that a substantial fraction of cosmic-ray...
Astrometry in the Gaia era will give an unprecedented amount of information about the full 6D phase space distribution of the local galactic halo. In this talk, I will use an analysis of vertical motions to show how the Gaia data will be sensitive to the presence of structures including dark disks (either from novel dark matter microphysics or from baryonic dragging.)
We present our first results from a deep LBT survey of dwarf satellites of nearby star-forming galaxies outside the local group. We present our candidates and report the number and distribution of satellites for our first system. We are sensitive to deep within the ultra faint dwarf and ultra diffuse galaxy regime outside. We discuss the implications of these new observations on the dark...
We study and constrain the impact of non-standard neutrino interactions on the CMB angular power spectrum. Starting from the collisional Boltzmann equation, we derive the Boltzmann hierarchy for neutrinos including interactions with a massive scalar particle.
In contrast to the Boltzmann hierarchy for photons, our interacting neutrino Boltzmann hierarchy is momentum dependent, which reflects...
The DeepCore infill array of the IceCube Neutrino Observatory enables observations of atmospheric neutrinos with energies as low as 5 GeV. Using a set of 40,000 neutrino events with energies ranging from 5.6 - 56 GeV recorded during three years of DeepCore operation, we measure the atmospheric oscillation parameters $\theta_{23}$ and $\Delta m^2_{32}$ with precision competitive with...
When analyzed together, radio and gamma-ray observations make for a very powerful tool for studying and diagnosing extragalactic cosmic ray populations. The recent gamma-ray detection of the ultra-luminous galaxy Arp 220 is well above past predictions, indicating evidence of a very large cosmic ray population. Whether the star formation or an active galactic nucleus is the source of the...
It has been suggested that high-energy gamma-ray emission ($>$100MeV ) of nearby star-forming galaxies may be produced predominantly by cosmic rays colliding with the interstellar medium through neutral pion decay. The pion-decay mechanism predicts a unique spectral signature in the gamma-ray spectrum, characterized by a fast rising spectrum and a spectral break below a few hundreds of MeV. We...
Light sterile neutrinos with eV mass have been suggested by different anomalies observed in short-baseline neutrino experiments. These particles would have been produced in the Early Universe changing the amount of relativistic energy density by increasing the
effective number of relativistic species ($N_{\rm{eff}}$). This results in a conflict with existing cosmological bounds on primordial...
As is well known, dark matter direct detection experiments will ultimately be limited by a "neutrino floor," due to the scattering of nuclei by MeV neutrinos from, e.g., nuclear fusion in the Sun. Here we point out the existence of a new "neutrino floor" that will similarly limit indirect detection with the Sun, due to high-energy neutrinos from cosmic-ray interactions with the solar...
We identify new astrophysical signatures of NS-imploding DM, which could decisively test these hypotheses in the next few years.
First, NS-imploding DM forms ≪10−10 solar mass black holes inside NSs, thereby converting NSs into ∼1.5 solar mass BHs. This decreases the number of NS mergers seen by LIGO/VIRGO (LV) and associated merger kilonovae seen by telescopes like DES, BlackGEM, and ZTF,...
The repeating fast radio burst (FRB) 121102 was recently localized to a star-forming region in a dwarf host galaxy remarkably similar to those of superluminous supernovae (SLSNe) and long gamma-ray bursts (GRB), both of which were previously proposed to be powered by the birth of a millisecond magnetar. We demonstrate how a single magnetar engine can power both a SLSN and GRB, depending on the...
High-energy neutrinos are expected to be produced in cosmic-ray interactions with the solar atmosphere. The resulting neutrino flux is expected to offer insights into cosmic ray transport in the inner solar system and on solar magnetic fields. Besides the high theoretical interest in solar atmospheric neutrinos, an observed signal could be the first high-energy neutrino point source and...
The survey of the Galactic plane in TeV gamma-rays by H.E.S.S.
allows a systematic study of the population of pulsar wind nebulae
(PWNe) in this energy domain. We find a mild trend of decreasing
TeV luminosity with age, or decreasing spin-down power, as well as
a trend of increasing size with age. Older TeV PWNe are generally
displaced from the pulsar position, with offsets larger than...
The standard $\Lambda$CDM cosmological model has successfully explained large scale cosmological observations. However, there are some discrepancies between the $\Lambda$CDM predictions and measurements at small scales. Even though these discrepancies could be due to unaccounted effects on weak lensing analyses and/or numerical simulations, in this talk, I will explore the possibility of...
Optical Synchrotron emission from blazars is significantly polarized and the polarization probes the magnetic field structure in the jet. Rotations of the polarization angle in blazars reveal important information about the evolution of disturbances responsible for blazar flares. Early results indicated that such rotations might be coincident with unusual gamma-ray activity of such sources....
Blazars are thought to possess a relativistic jet that is pointing toward the direction of the Earth and the effect of relativistic beaming enhances its apparent brightness. Although numerous measurements have been performed, the mechanisms behind jet variability, creation, and composition are still debated.
We performed simultaneous gamma-ray and optical photopolarimetry observations
of 45...
New results from the Large Underground Xenon (LUX) detector, a 100-kg-scale, 2-phase xenon direct dark matter search experiment, will be shared. Dark matter, the missing ~25% of the mass-energy content of the universe, is sought in new ways, using effective field theory operators to extend the search to higher-mass Weakly Interacting Massive Particles (WIMPs), spin-dependent interaction...
IceCube is a cubic kilometer scale detector in the deep antarctic ice. The 5160 deployed digital optical modules lead to the unambiguous detection of astrophysical neutrinos using events starting inside the detector with deposited energies above 60 TeV. Lowering the energy threshold down to 1 TeV, while maintaining a >90% neutrino-pure sample, greatly increases statistics. We will present the...
I will discuss new signatures in direct detection experiments if part or all of the dark matter particles in nature are in the form of bound states. It will allow the sub-GeV dark matter candidates to be much more visible at dark matter and neutrino detectors.
I present the results of large kinetic simulations of particle acceleration at non-relativistic collisionless shocks, which allow an ab-initio investigation of diffusive shock acceleration (DSA) at the blast waves of supernova remnants, the most prominent sources of Galactic cosmic rays (GCRs).
Ion acceleration efficiency and magnetic field amplification are obtained as a function of the...
By using deep radio source catalogs currently available, we present a new blazar candidate catalog, BROS, which includes 56314 sources located at declination $\delta > -40^{\circ}$ and outside the Galactic Plane ($|b| > 10^{\circ}$). We picked up flat-spectrum radio sources of $\alpha > -0.5$ ($\alpha$ is defined as $F_{\nu} \propto \nu^{\alpha}$) from 0.15 GHz TGSS and 1.4 GHz NVSS catalogs....
The spectrum of Weakly-Interacting-Massive-Particle (WIMP) dark matter generically possesses bound states when the WIMP mass becomes sufficiently large relative to the mass of the electroweak gauge bosons. The presence of these bound states enhances the annihilation rate via resonances in the Sommerfeld enhancement, but they can also be produced directly with the emission of a low-energy...
We report a new measurement of the diffuse flux of high energy extraterrestrial neutrinos from the whole sky with energies of O(1 TeV) and above, that is predominantly sensitive to electron and tau flavors. We analyzed 4 years of IceCube data recorded from 2012-2015 focusing on neutrino-induced cascades. Cascades provide good energy resolution and have a lower atmospheric neutrino background...
Xenon-based dark matter experiments have been leading the field of direct detection for a decade now, as realized most recently by the PandaX, LUX, and now XENON1T results, setting increasingly stringent limits on WIMP scattering. The near-future commencement of construction of LUX and ZEPLIN’s 10-ton-scale scale-up, next-generation successor, LZ, will be discussed here. We plan on achieving...
Recent high-energy missions have allowed keeping watch over quasars in flaring states, which provide deep insights into the engine powered by supermassive black holes. However, having a quasar caught in a very bright flaring state is not easy requiring long surveys. Therefore, the observation of such flaring events represents a goldmine for theoretical studies.
Such a flaring event was...
I will discuss cosmic ray production at relativistic shocks. I will emphasize the differences expected for relativistic shocks compared to non-relativistic ones and examine possible applications such as relativistic supernovae and gamma ray bursts.
Understanding the properties of dark matter particle is a fundamental problem in particle physics and cosmology. The search of dark matter particle scattering off nuclei target using ultra-low background detector is one of the most promising technology to decipher the nature of dark matter. The XENON1T experiment, which is a dual phase detector with ~2.0 tons of xenon running at the Gran Sasso...
The LHC Dark Matter Working Group (LHC DM WG) brings together theorists and experimentalists to provide the benchmark models, interpretation, and characterisation needed for a robust and broad set of searches for dark matter at the LHC. I will discuss the work of the LHC DM WG, and its predecessor the ATLAS/CMS Dark Matter Forum---the interaction between theory and experiment, the types of...
The PandaX project consists of a series of xenon-based experiments, located at China JinPing underground Laboratory. The current experiment, PandaX-II, is a direct dark matter search experiment with a 500 kg-scale liquid xenon dual-phase time projection chamber. PandaX-II started physics data taking in 2016. In this talk we report latest results and the current status of the PandaX-II experiment.
With the installation of a fifth 28-m diameter telescope in the center of the array, the H.E.S.S. telescope array is now in its phase II, characterized by a low energy threshold below 100 GeV. The low-energy window is particularly appealing for extragalactic gamma-ray astronomy, because it allows the study of more distant sources, as well as sources characterized by softer spectra. In...
The X-ray emission from pulsar wind nebulae arises from particles accelerated at the shock that terminates the relativistic, strongly magnetized pulsar wind. However, conventional theories of particle acceleration break down at this shock, because the combination of low particle density and strong magnetic field places it outside the
domain of validity of MHD. We first discuss how particles...
New particles with long lifetimes are introduced by many extensions to the standard model and would produce striking and non-conventional signatures in collider experiments such as long-lived charged particles, highly displaced jets, and particles that come to a rest within the detector and later decay. We present the results of several recent searches for long-lived particles with the CMS...
The CRESST (Cryogenic Rare Event Search with Superconducting Thermometers) experiment aims at the direct detection of dark matter particles via their elastic scattering off nuclei. The target material consists of scintillating CaWO$_4$ single crystals operated as cryogenic detectors at a temperature of ~10mK. For several years, these crystals have successfully been produced within the...
Radio Galaxies are the most likely class of sources for the diffuse flux of high-energy neutrinos reported by the IceCube Collaboration as suggested by multi-messenger data. Here, the gamma-ray spectrum from four nearby radio galaxies (Centaurus A, PKS 0625-35, NGC 1275, and IC 310) is analyzed in order to constrain the spectral shape and intensity of their respective injected emission. Our...
MAGIC is a stereoscopic system of two imaging atmospheric Cherenkov
telescopes, located at the Roque de los Muchachos Observatory,
in La Palma (Spain) sensitive to gamma rays from few tens of GeV to tens of TeV. Pulsar physics is one of important topics in the MAGIC scientific program. In 2008, MAGIC for the first time detected VHE gamma-rays demission above 25 GeV from the Crab pulsar. Ever...
We present several complementary searches for low mass dijet resonances using a 35.9 inverse femtobarn data set of proton-proton collisions at 13 TeV collected with the CMS experiment at the LHC in 2016. One search uses the CMS scouting data stream concept to record larger data rates than otherwise possible. Another search uses an initial state radiation jet to overcome trigger thresholds and...
IceCube analyses which look for an astrophysical neutrino signal in the southern sky face a large background of atmospheric neutrinos and muons created in cosmic ray air showers. Earlier, it was found that rejecting events that deposit energy in the outer region of the detector reduces not only the muon background, but also the atmospheric neutrino background in the southern sky due to the...
The PICO collaboration uses superheated fluid detectors to attempt to directly detect interactions between dark matter particles and ordinary matter. These detectors can be operated in conditions under which they are insensitive to gamma and beta radiation, typically the dominant backgrounds for direct dark matter searches.
The PICO-60 bubble chamber is located 2km underground at SNOLAB in...
We present the latest results in the search for rare, exotic, and invisible Higgs boson decays in proton-proton collision events collected with the CMS detector at the LHC. The rich experimental program we describe, which includes searches for lepton flavor violation and decays to dark matter and light scalars, provides a wide ranging probe for physics beyond the standard model.
The wide range of probes of physics beyond the standard model (BSM) lead to the need for tools that consistently combine experimental results to make the most robust possible statements about the validity of new physics theories and the preferred regions of their parameter space. In this talk, I will introduce a new publicly released code for such studies: GAMBIT, the Global and Modular BSM...
We present prospects for IceCube to detect neutrino emission from Galactic TeV gamma-ray sources outlined in the HAWC Observatory's recently published 2HWC catalog. We do this by evaluating the sensitivity of two analyses using IceCube data. The first is a stacked analysis of promising point sources from the catalog which are chosen based on their high TeV photon fluxes and lack of association...
The blazar Mrk 501 is a well-known BL-Lac type object emitting very high energy photons interacting with the EBL despite the modest redshift and is highly variable across wavelengths down to timescales of a few minutes at TeV energies. This makes it an excellent laboratory for
studying particle acceleration and radiative emission processes in jets
through the spectral and temporal properties...
Only a handful of High Mass X-ray Binaries (HMXB) in our galaxy are known emitters of TeV gamma rays. The variable VHE emission from these sources are generally attributed to modulation by their orbital periods but the particle acceleration and gamma-ray production processes in these HMXBs are not well understood. In its 10 years of operation, VERITAS has observed 2 of these TeV emitting...
Recent Fermi-LAT observations of dwarf spheroidal galaxies in the Milky Way have placed strong
limits on the gamma-ray flux from dark matter annihilation. In order to produce the strongest limit
on the dark matter annihilation cross-section, the observations of each dwarf galaxy have typically
been “stacked” in a joint-likelihood analysis, utilizing optical observations to constrain...
Supernovae (SNe) and their remnants are important cosmic ray sources. However, the origin of one major type of SNe, the Type Ia, is still not well understood. Two most popular hypotheses are the single-degenerate scenario, where one white dwarf (WD) accretes matter from its giant companion until the Chandrasekhar limit is reached, and the double-degenerate scenario, where two WDs merge and...
Many extensions of the Standard Model of particle physics predict a parallel sector of at least one new U(1) symmetry, giving rise to hidden photons. If produced non-thermally in the early universe, these hidden photons can be candidate particles for cold Dark Matter. Hidden photons are expected to kinetically mix with regular photons. If hidden photons pass through a conducting surface a tiny...
I review our present observational understanding of the mysterious new phenomenon of Fast Radio Bursts -- short (few ms) bursts of radio waves arriving from apparently cosmological distances -- as well as models for what these sources may be. I also describe the CHIME telescope, currently being built in Canada, and how it will impact this interesting puzzle.
A new era in galactic cosmic rays physics has started with the precise and continuous observations from space experiments such as PAMELA and AMS-02. Their invaluable results are rewriting the theory of acceleration and propagation of cosmic rays. Both at high energies, where several new behaviors have been measured, challenging the accuracy of theoretical models, as well as at low energies, in...
In this talk I will review the status and prospects of understanding the physics of ultra-high-energy cosmic rays. Focusing on the progress made thanks to data of the Pierre Auger Observatory and Telescope Array, observations are discussed in the context of their implications for various source scenarios and remaining uncertainties are highlighted. The talk concludes with a summary of ongoing...
Magnetic fields are ubiquitous in the Universe. The energy density of these fields is typically comparable to the energy density of the fluid motions of the plasma in which they are embedded. Magnetic fields are also essential for the production of high energy cosmic rays. The standard theoretical model for the origin of these strong magnetic fields is through the amplification of tiny seed...
I will review several interesting anomalies in cosmic-ray (CR) and gamma-ray data and discuss possible interpretations, focusing on what they can reveal about the nature of CR sources and the physics of CR transport in the Galaxy.
The first year of the Dark Energy Survey observations imaged 1321 square degree of the Southern sky in griz. We present measurements of galaxy clustering and weak gravitational lensing from this data set, and cosmological parameters inferred from these these two-point correlation functions in a blind analysis.
Advanced LIGO's ongoing observation runs provided humanity with the first direct detection of gravitational waves, just in time for the 100th anniversary of Einstein's prediction. Beyond the discovery, there is a growing focus on incorporating gravitational waves as a new window on questions from violent transients to cosmology. I will discuss some aspects of (i) the instrumental breakthroughs...
Recent results on the Extragalactic Background Light (EBL) intensity obtained from a combined likelihood analysis of blazar spectra detected by the MAGIC telescopes are reported. The EBL is the optical-infrared diffuse background light accumulated during galaxy evolution, directly and/or reprocessed by dust, which provides unique information about the history of galaxy formation. The low...
Extragalactic galaxies and galaxy clusters are expected to be some of the brightest sources of dark matter annihilation on the sky. Further, catalogs such as the 2MASS survey, tell us where thousands of these objects are. The challenge, however, is that catalogs only detail a subset of the baryonic properties of these galaxies. In this talk I will outline how to map from a catalog of galaxies...
Knowledge of the energy dependence of the 3He-to-4He flux ratio (3He/4He) is important in understanding the propagation of cosmic rays. As 3He is assumed to be produced by interactions of heavier nuclei with the interstellar matter, the 3He/4He ratio is a powerful tool for determining the amount of interstellar material traversed by cosmic rays. AMS results are based on 9 million 3He events...
We perform a search for dark matter (DM) annihilation in nearby galaxies using 413 weeks of publicly-available Fermi Pass 8 gamma-ray data, utilizing a novel method that takes advantage of recently-developed galaxy group catalogs based on the 2MASS Redshift Survey. Having validated our method using N-body simulations, we construct nearly all-sky maps of an expected DM annihilation signal in...
In recent years, advances in numerical methods have allowed us to calculate precision observables with fewer assumptions. Here I will discuss two of these observables, Hubble Diagrams and the Weak Lensing Convergence Power Spectrum. I will comment on the role that inhomogeneities, entering at high order, effects cosmological measurements.
We have calculated the extragalactic IR-UV photon density as a function of redshift, and the resulting IR-UV spectrum of the extragalactic background light. Our empirically-based approach is based on local-to-deep galaxy survey data obtained in different wavelength bands using many space-based telescopes. This approach allowed us, for the first time, to obtain a completely model independent...
Supernova remnants are known to be the main sources of galactic cosmic-rays.
They could also be a possible explanation for rise of the positron fraction,
if secondary positrons are produced and then accelerated around the supernova shock front. Yet, if secondary positrons are stochastically accelerated in such shocks,
other secondary cosmic ray species will also be accelerated. Using recent...
I present my recent paper arXiv:1704.05073 on making projections for measuring the black hole birth rate from the diffuse supernova neutrino background (DSNB) by future neutrino experiments, and the information which can be gained by combining this with the merger rate from LIGO. The DSNB originates from neutrinos emitted by all the supernovae in the Universe, and is expected to be made up of...
The role of cosmic rays generated by supernovae and young stars has very recently begun to receive significant attention in studies of galaxy formation and evolution due to the realization that cosmic rays can efficiently accelerate galactic winds. Microscopic cosmic ray transport processes are fundamental for determining the efficiency of cosmic ray wind driving. Previous studies focused on...
I will describe how statistical anisotropies, such as dipole modulations of the cosmic microwave background temperature and polarization fluctuations, are more likely if the primordial fluctuations are non-Gaussian. I will then discuss the implications of this effect for observations in the cosmic microwave background temperature and polarization anisotropies, and how such observations can be...
Milky Way dwarf spheroidal satellite galaxies are the most dark-matter-dominated galaxies known. Due to their proximity, high dark matter content, and lack of astrophysical backgrounds, dwarf spheroidal galaxies are one of the most promising targets for the indirect detection of dark matter annihilation via gamma rays. Indeed, Fermi-LAT observations of previously known dwarf galaxies have...
Gamma-rays with energy exceeding 100 GeV emitted by extragalactic sources initiate cascades in the intergalactic medium. The angular and temporal distribution of the cascade photons that arrive at the Earth depend on the strength and configuration of extragalactic magnetic fields in the line of sight. For weak enough fields, extended emission around the source (halo) is expected to be...
In this talk we will present the latest development of the CLUMPY code. The first version aimed at the calculation of the astrophysical J-factors from dark matter annihilation/decay in any galaxy or galaxy cluster dark matter halo including substructures. While refining on several aspects of the first version (halo-to-halo concentration scatter, multi-level boost factors, and triaxiality), the...
We study gravitational wave (GW) production from bubble dynamics
during a cosmic first-order phase transition
by using the method of relating the GW spectrum to the two-point correlation function
of the energy-momentum tensor < T(x) T(y) >.
We adopt the thin-wall approximation but not the envelope approximation,
and take the (long-lasting) non-envelope parts into account by assuming free...
We report on the Fermi High-Latitude Extended Source Catalog (FHES), a systematic search for spatial extension of gamma-ray point sources detected with the Fermi Large Area Telescope (LAT) at Galactic latitudes |b| > 5 degrees. Point sources listed in the 3FGL and 3FHL catalogs are used for this search. While the majority of high-latitude LAT sources are extragalactic blazars that appear...
We evaluated flux of cosmic ray anti-deuteron and anti-Helium3 from secondary astrophysical production.
The production cross section at proton-proton collision is one of the most important input parameter to determine the secondary cosmic ray flux. However, composite (anti-)nuclei production cross section is very small and the cross section data at collider experiments is quite limited. That...
For models in which dark matter annihilation is Sommerfeld-enhanced, the annihilation cross section increases at low relative velocities.
Dwarf spheroidal galaxies (dSphs) have low characteristic dark matter particle velocities and are thus ideal candidates to study such models.
We model the dark matter phase space of dSphs as isotropic and spherically-symmetric and determine the $J$-factors...
Particles present in the early Universe can leave observable imprints if they affect dark matter properties after dark matter has gone out of equilibrium with the thermal bath. We will investigate such possibilities and their associated observable signatures in several well-motivated dark matter frameworks.
Measurements of the Geminga and B0656+14 pulsars by HAWC and Milagro indicate that these objects generate significant fluxes of very high-energy electrons. From the very high-energy gamma-ray intensity and spectrum of these pulsars, one can calculate their expected contributions to the local cosmic-ray positron spectrum. From these considerations, we find that pulsars produce a flux of...
The very high energy ($E > 100 $ GeV) gamma-ray flux from extragalactic sources is attenuated due to $e^+e^-$ pair production on the extragalactic background light (EBL). This attenuation process can lead to the development of electromagnetic cascades from the inverse-Compton scattering of background photons by the produced $e^+e^-$ pairs. The cascade secondary gamma-ray emission is...
The CALorimetric Electron Telescope (CALET) space experiment, which has been developed by Japan in collaboration with Italy and the United States, is a high-energy astroparticle physics mission to be installed on the International Space Station (ISS). The primary goals of the CALET mission include investigating possible nearby sources of high energy electrons, studying the details of galactic...
Poisson regression of the Fermi-LAT data in the inner Milky Way reveals an extended gamma-ray excess. An important question is whether the signal is coming from a collection of unresolved point sources, possibly old recycled pulsars, or constitutes a truly diffuse emission component. Previous analyses have relied on non-Poissonian template fits or wavelet decomposition of the Fermi-LAT data,...
We propose a novel method to search for signatures of dark matter annihilation in Galactic substructure using gamma-ray data from the $\it Fermi$ Large Area Telescope. The method takes advantage of the fundamentally different photon-count statistics that describe dark matter annihilation from a population of subhalos versus from the smooth Milky Way halo. In addition, it exploits differences...
Milky Way satellite dwarf galaxies are among the oldest, smallest, and most dark matter dominated galaxies in the known Universe. The study of these tiny galaxies can help shed light on the nature of dark matter and the mysteries of galaxy formation. Over the last two years, efforts using the Dark Energy Camera (DECam) have nearly doubled the known population of Milky Way satellite galaxies....
In this talk, we discuss a scenario called late-decaying two-component dark matter (LD2DM), where the entire DM consists of two semi-degenerate species. Within this framework, the heavier species is produced as a thermal relic in the early universe and decays to the lighter species over cosmological timescales. Consequently, the lighter species becomes the DM which populates the universe...
The objectives of the Pierre Auger Observatory are to probe the origin and characteristics of cosmic rays above $10^{17}$ eV and to study the interactions of these, the most energetic particles observed in nature. The Observatory design features an array of water Cherenkov stations deployed over a surface of $3000$ km$^2$ overlooked by fluorescence telescopes. This design and a sophisticated...
The WFIRST high-latitude survey (HLS) will provide an exciting dataset for constraining dark energy through a variety of measurement methods. In this talk, I will describe the current plans for the WFIRST HLS and the potential for competitive constraints on dark energy with weak lensing. I will also discuss the potential synergies with other surveys during the same time-frame, including the...
All models for Galactic diffuse gamma-ray emission share one property: They
give formally a remarkably bad fit to the data. A large number of statistically significant residuals remain, making it very challenging to discriminate genuine features in the data from analysis artefacts.
We present SkyFACT (Sky Factorization with Adaptive Constrained Templates) [1], a new approach for studying,...
The Astrophysical Multimessenger Observatory Network (AMON), will connect observatories from around the world, enabling real-time coincidence searches of all four messengers (neutrinos, cosmic rays, gamma rays, and gravitational waves) and rapid follow-up observations of these alerts. AMON’s first real-time alerts were commissioned in 2016 with “pass-through” notices of IceCube likely-cosmic...
The High-Altitude Water-Cherenkov (HAWC) experiment is a TeV gamma-ray
observatory located at 4100 m above sea level on the Sierra Negra mountain in
Puebla, Mexico. Each of the detector's 300 water-filled tanks is instrumented
with four photomultiplier tubes that detect the Cherenkov radiation produced by
charged particles created in extensive air showers. With an instantaneous
field of view...
The Telescope Array (TA) measures the properties of ultra high energy cosmic ray (UHECR) induced extensive air showers. TA employs a hybrid detector comprised of a large surface array of scintillator detectors overlooked by three fluorescence telescopes stations. The TA Low Energy extension (TALE) detector has operated as a monocular Cherenkov/fluorescence detector for nearly three years, and...
Fast radio bursts (FRBs) are non-periodic millisecond radio outbursts that are thought to be of astrophysical origin. Since the first FRB was discovered by the Parkes Radio Telescope in 2007, a total of 23 FRBs with unique locations (FRB 121102 has repeated dozens of times) have been observed to date, with multiple radio telescopes. Although the nature of the FRBs is still largely unknown, the...
The most dramatic "Sommerfeld enhancements'' of neutral-wino-pair annihilation occur when the wino mass is near a critical value where there is a zero-energy S-wave resonance at the neutral-wino-pair threshold. Near a critical mass, low-energy winos can be described by a zero-range effective field theory in which the winos interact nonperturbatively through a contact interaction. The...
We present a self-consistent model of the Fermi Bubbles, described as a decelerating outflow of gas and non-thermal particles produced within the Galactic center region, on a $\sim 100$ Myr timescale. Motivated by observations, we use an outflow with velocity O(100 km/s), which is slower than the velocities used in models describing the Bubbles as a more recent outburst. We take into account...
I will present a suite of new algorithms for measuring higher-point statistics from large-scale structure surveys. I will begin with a transformatively-fast algorithm that enables computation of the isotropic 3-point correlation function scaling as the number of galaxies squared. This algorithm was applied to BOSS data to make the first high-significance detection of the Baryon Acoustic...
The flux of cosmic rays is observed at the Pierre Auger Observatory spanning almost three decades in energy. This energy range is possible by combining the measurements from the nested 1500 m and 750 m surface detector arrays. The energy scale relies on the almost calorimetric energy measurements performed with Auger's fluorescence detectors. With a total exposure of about 52000 [km^2 sr yr]...
In this talk, I will discuss a class of models in which thermal dark matter is lighter than an MeV. If dark matter thermalizes with the Standard Model below the temperature of neutrino-photon decoupling, constraints from measurements of the effective number of neutrino species are alleviated. This framework motivates new experiments in the direct search for sub-MeV thermal dark matter and...
We analyze the Extended Quasi-Dilaton Massive Gravity model around a Friedmann-Lemaitre-Robertson-Walker cosmological background. We present a careful stability analysis of asymptotic fixed points. We find that the traditional fixed point cannot be approached dynamically, except from a perfectly fine-tuned initial condition involving both the quasi-dilaton and the Hubble parameter. A...
The Fluorescence detector Array of Single-pixel Telescopes (FAST) is a design concept for the next generation of Ultra-High-Energy Cosmic Ray (UHECR) observatories, addressing the requirements for a large-area, low-cost detector suitable for measuring the properties of the highest energy cosmic rays. In the FAST design, a large field of view is covered by a few pixels at the focal plane of an...
We investigate the feasibility of the indirect detection of dark matter in a simple model using the neutrino portal. The model is very economical, with right-handed neutrinos generating neutrino masses through the Type-I seesaw mechanism and simultaneously mediating interactions with dark matter. Given the small neutrino Yukawa couplings expected in a Type-I seesaw, direct detection and...
Cosmic rays can be probed by their non thermal emission in the radio and in gamma-ray bands. One-zone models of cosmic rays have been used to match the integrated emission of starburst galaxies. We construct multi-dimensional models of the local starburst M82 using cosmic ray propagation code GALPROP. Using the integrated gamma-ray and radio spectra, along with the vertical distribution of...
Compact astrophysical sources represent the most extreme and powerful end-points of the life of massive stars. They power relativistic and magnetized plasma which interact with the ambient medium, leading to a large variety of phenomena observable in the high- and very-high energy regime. In particular the complex Pulsar/Pulsar Wind-Nebulae/Supernova Remnant blast provides an optimal scenario...
I will present the most recent results from two years of HAWC data.
The annihilation of dark matter can lead to observable signatures in
high-energy gamma rays. I will review the
current status of such dark matter searches with data from the Fermi Large
Area Telescope. In particular, I will discuss searches within the Milky Way and Local Group, and present results from a new study that uses galaxy surveys to improve sensitivity to signals of extragalactic...
Extragalactic jets are the largest particle accelerators in the universe, producing radiation ranging from radio wavelengths up to very high-energy gamma rays. Spatial origin of gamma-ray radiation from these sources cannot be fathom due to the poor angular resolution of the detectors. We propose to investigate gravitationally lensed blazars. Cosmic lenses magnify the emission and produce time...
In models of early universe cosmology, primordial magnetic fields with helicity can be created during cosmological inflation, and they may play a role in the generation of the matter / antimatter asymmetry of the universe. Such a primordial magnetic field will persist in the universe today as an intergalactic magnetic field, and the discovery of this cosmological relic will open a new window...
Neutrino interactions, though feeble, are tremendously important in particle physics and astrophysics. Still, at neutrino energies above ~350 GeV there has been, up to now, no direct experimental information on neutrino interactions; calculations rely on extrapolations from lower energies. Now, for the first time, we can measure the neutrino-nucleon cross section at the TeV scale and above,...
Predictions for direct dark matter searches rely on the knowledge of the local speed distribution of dark matter particles. This distribution can be derived within a dynamically constrained Milky Way mass model using the Eddington formalism or some extended versions of it. This method, however, can lead to unconsistent or unphysical solutions, depending on the details of the mass model. I will...
The ALPACA (Andes Large area PArticle detector for Cosmic ray physics and Astronomy) experiment is aimed at observing cosmic gamma rays above 10 TeV in the southern sky with wide field of view and high sensitivity.
We will construct an 83,000 m^2 surface air-shower array and a 5,400 m^2 underground muon detector array,
on a highland (Chacaltaya Hill) at the altitude of 4,740 m halfway up Mt....
Hyper Suprime-Cam (HSC) is an imaging camera mounted at the Prime Focus of the Subaru 8.2-m telescope operated by the National Astronomical Observatory of Japan on the summit of Maunakea in Hawaii. A consortium of astronomers from Japan, Taiwan and Princeton University is carrying out a three-layer, 300-night, multiband survey from 2014-2019 with this instrument. In this talk, I will focus on...
The MeV domain is one of the most underexplored windows on the Universe. From astrophysical jets and extreme physics of compact objects to a large population of unidentified objects, fundamental astrophysics questions can be addressed by a mission that opens a window into the MeV range. AMEGO is a wide-field gamma-ray telescope with sensitivity from ~200 keV to >10 GeV. AMEGO provides three...
The interpretation of dark matter direct detection results is complicated due to the unknown distribution of dark matter in our local neighborhood. Astrophysical uncertainties in the dark matter distribution are a major barrier preventing a precise determination of the properties of the dark matter particle. High resolution cosmological simulations of galaxy formation including baryons have...
CHIME will use the 21cm emission line of neutral hydrogen to map large-scale structure between redshifts of 0.8 and 2.5. By measuring Baryon Acoustic Oscillations (BAO) we will place constraints on the dark energy equation of state as it begins to dominate the expansion of the Universe, particularly at redshifts poorly probed by current BAO surveys.
In this talk I will introduce CHIME, a...
Type Ia supernovae (SNe Ia) provided the first direct evidence for the accelerated expansion of the universe, leading to the now-standard Lambda-CDM model featuring dark energy. Beyond direct dark energy measurements, these accurate standard candles can be employed in a variety of ways to test the Lambda-CDM model. I will show how an analysis of the peculiar velocities of SNe Ia constitutes a...
The Lunar Occultation Explorer (LOX) is a paradigm shift - a next-generation mission concept that will provide new capabilities in time-domain nuclear astrophysics and establish the Moon as a platform for nuclear astrophysics. Currently under review by NASA’s Explorer Program, LOX's performance requirements are driven by focused science goals designed to resolve the enigma of Type-Ia supernova...
The Interstellar Boundary Explorer (IBEX) is an Earth-orbiting spacecraft equipped with two single-pixel cameras that detect neutral atoms produced by the interaction of the solar wind (SW) with the very local interstellar medium (VLISM), as well as neutral atoms flowing in from the VLISM itself. After its launch in 2009, IBEX discovered the unexpected existence of the “ribbon,” a nearly...
Many dark matter studies have considered indirect detection (χχ → ff), direct detection (χf →χf ), and collider searches (ff → χχ). We propose a new strategy in searching for dark matter elastic cross section by considering cosmic-ray propagation in the galactic dark matter halo. We find that cosmic rays can lose significant fraction of their energy through scattering with dark matter (fχ → fχ)....
In 2015, the HAWC Observatory was completed and began operation as the most sensitive TeV cosmic-ray detector in the Northern Hemisphere. Since that time, we have recorded over 1 trillion cosmic-ray air showers, designed a likelihood-based cosmic-ray energy reconstruction, and implemented a new minimally-biased method for reconstructing all-sky anisotropy. These three advances in statistics,...
We study Lorentz violation effects to flavor transitions of high energy astrophysical neutrinos. It is shown that the appearance of Lorentz violating Hamiltonian can drastically change the flavor transition probabilities of
astrophysical neutrinos. Predictions of Lorentz violation effects to flavor compositions of astrophysical neutrinos arriving on Earth are compared with IceCube flavor...
In this talk, we discuss the effects of a non-negligible threshold energy on our model-independent methods developed for reconstructing WIMP properties by using measured recoil energies in direct Dark Matter detection experiments directly. Our expressions for reconstructing the mass and the (ratios between the) spin-independent and the spin-dependent WIMP-nucleon couplings have been modified....
We present some of the main results from the Third Catalog of Hard Fermi-LAT Sources (3FHL). This catalog, based on the first 7 years of LAT data using the Pass 8 event-level analysis, contains 1556 sources characterized in the 10 GeV--2 TeV energy range. The sensitivity and angular resolution are improved by factors of 3 and 2 relative to the previous LAT catalog in this energy range (1FHL)....
Although cosmic rays are nearly isotropic, ground-based arrays sensitive to TeV cosmic rays have measured a small anisotropy in right ascension. Understanding the morphology and energy dependence of this anisotropy can yield insight into cosmic-ray sources and propagation in the local magnetic field. The Fermi Large Area Telescope (LAT) is optimized for gamma-ray measurements, but it records...
If dark energy is some kind of scalar field rather than a cosmological constant and can interact with the neutrino sector, it might cause CPT/Lorentz violating effects and also modifies the neutrino oscillation phenomenology. The effects will be insignificantly small compared to the ordinary oscillation effect at low energies, but might become visible in very high energies, since the terms in...
We discuss direct detection of WIMP dark matter in two benchmark cases: a Majorana fermion that primarily interacts via the Z-boson, and a Majorana fermion whose relic density is primarily set via co-annihilations with colored partners. We discuss the Z-mediated case with reference to a simple UV-completion, the singlet doublet model. We discuss the co-annihilation case with reference to...
ABRACADABRA is a proposed experiment to search for ultralight (10^-14 - 10^-6 eV) axion dark matter. When ultralight axion dark matter encounters a static magnetic field, it sources an effective electric current that follows the magnetic field lines and oscillates at the axion Compton frequency. In the presence of axion dark matter, a large toroidal magnet will act like an oscillating current...
The High-Altitude Water Cherenkov (HAWC) TeV Gamma-Ray Observatory in Mexico is a wide-field-of-view telescope with a nearly 100 % duty cycle. It has been taking data with a complete detector configuration since spring 2015 and is particularly well suited to measure very energetic transient and extended gamma-ray emission in our Galaxy. In my presentation, I will give an overview of the most...
Neutrino spectral indices Galactic vs. Extra-galactic sources, and potential use of Glashow events are analyzed.
We have discovered a rare new form of long-term radio variability in the light-curves of active galaxies (AG) (arXiv:1702.06582, arXiv:1702.05519) --- Symmetric Achromatic Variability (SAV) --- a pair of opposed and strongly skewed peaks in the radio flux density observed over a broad frequency range. We propose that SAV arises through gravitational milli-lensing when relativistically moving...
I will revisit the production of baryon asymmetries in the minimal type I seesaw model with two heavy Majorana singlets in the GeV range. Beside the tree level top scattering we include scattering processes on gauge bosons as well as $1\rightarrow 2$ processes of Higgs decay and inverse decays, that can contribute significantly to the wash-out effect.
I will show that the region of parameter...
In this talk I will discuss a model in which the matter / anti-matter asymmetry of the universe is generated during a first order cosmological phase transition associated with the spontaneous breaking of lepton-number, which gives rise to the Majorana mass for heavy sterile neutrinos. The dynamics leading to lepton-number generation, namely CP-violating scattering at a bubble wall, are...
The IceCube neutrino discovery was punctuated by three showers with $E_\nu$ ~ 1-2 PeV. Interest is intense in possible fluxes at higher energies, though a marked lack of $E_\nu$ ~ 6 PeV Glashow resonance events implies a spectrum that is soft and/or cutoff below ~few PeV. However, IceCube recently reported a through-going track event depositing 2.6 $\pm$ 0.3 PeV. A muon depositing so much...
The nature of dark matter (DM) remains one of the fundamental questions in cosmology. Axions are one of the current leading candidates for the hypothetical, non-baryonic DM. Especially in the light of LHC slowly closing in on WIMP searches, axions and axion-like particles (ALPs) provide a viable alternative approach to solving the dark matter problem. The fact that makes them very appealing is...
The jets of active galactic nuclei (AGN) are among the most powerful systems in the Universe. Their emission spans over an extremely wide energy range, from radio to gamma-rays or even TeV energies, and often shows pronounced variability with timescales anywhere between a few years and several minutes. Therefore, high-cadence, multi-band monitoring programs are essential in the investigation...
After the discovery of extraterrestrial high-energy neutrinos, the next major goal of neutrino telescopes will be identifying astrophysical objects that produce them. The flux of the brightest source Fmax, however, cannot be probed by studying the diffuse neutrino intensity. We aim at constraining Fmax by adopting a broken power-law flux distribution, a hypothesis supported by observed...
I will introduce the MATHUSLA proposal (Massive Timing Hodoscope for Ultra-Stable neutraL pArticles) for a ~200mx200m tracker above ATLAS or CMS at the HL-LHC. Its primary purpose is the search for exotic long-lived particles with lifetimes up to the BBN bound of ~ 0.1 seconds, where it would extend LHC sensitivity by orders of magnitude. In addition, the design and position of MATHUSLA close...
The HAWC (High Altitude Water Cherenkov) observatory recently published their second source catalog with 39 very high energy gamma-ray sources based on 507 days of exposure time. We studied thirteen HAWC sources without known counterparts with VERITAS and Fermi-LAT data. VERITAS, an array of four imaging atmospheric Cherenkov telescopes observing gamma rays with energies higher than 85 GeV,...
We propose the first viable radiative seesaw model, in which the neutrino masses are induced radiatively via the two-loop Feynman diagram involving Strongly Interacting Massive Particles (SIMP). The stability of SIMP dark matter (DM) is ensured by a Z5 discrete symmetry, through which the DM annihilation rate is dominated by the 3 to 2 self-annihilating processes. The right amount of thermal...
The 2HWC gamma-ray catalog was recently released using 17 months of data from the HAWC observatory, a TeV surveying instrument located in Mexico. A total of 39 sources were detected, of which ~40% are not near known TeV sources and over half do not have clear association with known astrophysical sources. Many are extended and encompass multiple known X-ray and gamma-ray sources. In an effort...
Neutrinos from supernovae (SNe) are crucial probes of explosive phenomena at the deaths of massive stars and neutrino physics. High-energy neutrinos are produced through hadronic processes by cosmic rays, which can be accelerated during interaction between the SN ejecta and circumstellar material (CSM). We investigate high-energy neutrino emission from Galactic SNe. Recent observations of...
While the discovery of the Higgs boson at the LHC experimentally confirms the widely successful Standard Model (SM) of particle physics, the theory still falls short of explaining several fundamental features of our Universe. A major shortcoming is the SM’s silence on the nature of Dark Matter (DM). Currently, axions and WIMPs are the leading DM candidates with axions simultaneously addressing...
Gamma ray astronomy provides a powerful way to study particle acceleration and diffusion within high-energy astrophysical phenomena such as supernova remnants and pulsar wind nebulae. Constructing a coherent physical picture of these sources requires the ability to detect extended regions of gamma-ray emission, the ability to analyze small-scale spatial variation within these regions, and the...
Type IIn supernovae (SNe) explode in dense circumstellar media that have been modified by the SNe progenitors at their last evolutionary stages. The interaction of the freely expanding SN ejecta with the circumstellar medium gives rise to a shock wave propagating in the dense SN environment, which may accelerate protons to multi-PeV energies. Inelastic proton-proton collisions between the...
The J-PARC Sterile Neutrino Search at the J-PARC Spallation Neutron Source (JSNS$^2$) will search for neutrino oscillations with $\Delta m^2 \sim$ 1 eV$^2$ at the J-PARC Material and Life Science Experimental Facility (MLF). The experiment will perform a search for $\bar{\nu}_\mu \rightarrow \bar{\nu}_e$ oscillations over a 24 m baseline using muon decay at rest neutrinos originating from 3...
Extensive observations by Fermi, AGILE, and TeV telescopes have opened a new window into the high-energy physical processes of AGNs and raised questions about the physics of their jets, their formation and cosmological evolution, and their impact on their environments and the growth of structure in the Universe. Multiwavelength observations in X-rays and at GeV and TeV energies point to a...
Star-forming and starburst galaxies are among candidate sources of high energy neutrino flux detected in the IceCube experiment. Previous studies mainly used simple correlations between gamma-ray and infrared luminosities and assume a common value of gamma-ray spectral index for all starburst galaxies, though it should depend on properties of individual galaxies. In this work, we present a new...
The number of nonrelativistic axions can be changed by inelastic reactions
that produce relativistic axions or photons.
Any even number of nonrelativistic axions can scatter inelastically into two relativistic axions. Any odd number of axions can annihilate into two photons.
This reaction produces a monochromatic radio-frequency signal at an odd-integer harmonic of the fundamental frequency...
The Cygnus region consists of multiple gamma-ray source types such as pulsar wind nebulae (PWN), supernova remnants, binary systems, and star clusters. Several gamma-ray instruments have observed gamma-ray sources in this region. For instance, Fermi-LAT found gamma-ray emission at GeV energies due to a Cocoon of freshly accelerated cosmic rays, which is co-located with a known PWN seen by...
In this talk we will present novel ways in which neutrino oscillation experiments can probe dark matter. In
particular, we focus on interactions between neutrinos and ultra-light (“fuzzy”) dark matter particles
with masses of order $10^{-22}$ eV. It has been shown previously that such dark matter candidates are
phenomenologically successful and might help ameliorate the tension between...
Despite intensive research, some fundamental properties of the most luminous particle accelerators and transients like AGNs, GRBs, etc. are unknown. Location and mechanisms of particle acceleration, connection to flaring and quiescent states, leptonic vs hadronic emission are open questions. Complexity of environments and processes make it hard to disentangle different scenarios. This suggests...
Giant Molecular Clouds (GMC) are large reservoirs of gas and dust in the galaxy, which makes them ideal for the production of gamma-ray emission due to the interaction of cosmic rays with the ambient gas. This gamma-ray emission is part of the galactic diffuse gamma-ray emission, which is useful for tracing the propagation and distribution of cosmic rays throughout our Galaxy. The search of...
ABRACADABRA10cm is a new experiment which seeks to detect
axion dark matter through its interactions with the electromagnetic field. The experiment, which is planned to start collecting data this year, will probe unstudied regions of axion parameter space and lay the groundwork for future, larger-scale efforts. I will discuss the results of numerical and analytical work...
High energy neutrinos have been detected by IceCube, but their origin remains a mystery. Determining the sources of this flux is a crucial first step towards multi-messenger studies. In this work we systematically compare two classes of sources with the data: galactic and extragalactic. We build a likelihood function on an event by event basis including energy, event topology, absorption, and...
Neutron tagging is a promising experimental technique for separating between signal and background in a wide variety of astroparticle measurement. The Accelerator Neutrino Neutron Interaction Experiment (ANNIE) located along the Booster Neutrino Beam at Fermilab has a goal of measuring the final state neutron multiplicity from charged current neutrino-nucleus interactions within the...
MicroBooNE is a liquid argon TPC neutrino experiment based at Fermilab and situated on the Booster Neutrino Beam. MicroBooNE's primary aim is to investigate the excess of electron neutrino-like events seen by the MiniBooNE experiment, which is potential evidence for new non-Standard physics such as sterile neutrinos. This talk will discuss a search for low-energy electron neutrino interactions...
The High Altitude Water Cherenkov (HAWC) gamma-ray observatory is a continuously operated, wide field-of-view (FOV) observatory sensitive to 100 GeV - 100 TeV gamma rays and cosmic rays. HAWC has been making observations since summer 2012 and officially commenced data-taking operations with the full detector in March 2015. With an FOV of 2 steradians, HAWC observes 2/3 of the sky in 24 hours. ...
The recent observations of powerful, minute-timescale TeV flares from
several blazars pose serious challenges to theoretical models for the
blazar emission. In this talk, I will discuss the magnetic
reconnection model for the blazar flaring. I argue that radiation
emitted from the reconnection layers can account for the observed
“envelope” of ~day-long blazar activity as well as the fastest
...
The first and second observational runs of the Advanced LIGO and Virgo detectors are seeing the first detections of gravitational waves (GWs) from binary black holes. Future observational runs by advanced gravitational-wave detectors should measure not only stellar-mass binary black hole mergers but other compact object mergers that comprise neutron stars. We expect such systems to emit...
The fundamental properties of dark matter, such as its mass, self-interaction, and coupling to other particles, can have a major impact on the evolution of cosmological density fluctuations on small length scales. Strong gravitational lenses have long been recognized as powerful tools to study the dark matter distribution on these small subgalactic scales. In this talk, we discuss how...
The gamma-ray emission that arises from charged particle interactions with ambient photons and interstellar material provides insight into the nature and mechanism of charged particle (cosmic ray) acceleration taking place within the phenomena left behind by the death of massive stars: i.e. supernova remnants (SNRs) and pulsar wind nebulae (PWNe). The very-high-energy (VHE) gamma-ray...
The DArk Matter Particle Explorer (DAMPE), is a space mission within the strategic framework of the Chinese Academy of Sciences, resulting from a collaboration of Chinese, Italian, and Swiss institutions, is a new addition to the growing number of particle detectors in space. It was successfully launched in December 2015 and has commenced nominal science operations since shortly after launch....
Very high energy gamma-rays produced by extragalactic sources are absorbed in the intergalactic medium. High energy photons interact with low energy photons from the extragalactic background light (UV to IR) producing pairs of electron - positrons. Newly created leptons scatter CMB photons to gamma-ray energies. Spectral properties, halo extension and time delay due to the cascade strongly...
One of the best current constraints for indirect detection of dark matter at the 1-100 GeV mass scale is the Fermi-LAT stacking analysis of satellite dwarf galaxies of the Milky Way. This constraint is based on observations in a very small fraction of the sky, whereas undetectable, dense dark matter structures are predicted to be distributed throughout the Milky Way halo. I will describe...
In this talk, I will present the status and plans of a new dedicated experiment called milliQan that we propose to install at LHC Point 5. It is designed to be sensitive to particles produced in pp collisions that have EM charges ranging from 0.001 e to 0.1 e, as can arise in a variety of beyond-the-standard model scenarios.
A Type Ia supernova (SNIa) could go entirely unnoticed in the Milky Way and nearby starburst galaxies, due to the large optical and near-IR extinction in the dusty environment, low radio and X-ray luminosities, and a weak neutrino signal. But the recent SN2014J confirms that Type Ia supernovae emit γ-ray lines from $^{56}$Ni→$^{56}$Co→$^{56}$Fe radioactive decay, spanning 158 keV to 2.6 MeV....
There is overwhelming evidence that non-baryonic dark matter constitutes ~85% of the mass in the Universe. Many promising dark matter candidates, like Weakly Interacting Massive Particles (WIMPs), are predicted to produce Standard Model particles like gamma rays via annihilation or decay. These gamma-rays would be observed by ground-based arrays like the High Altitude Water Cherenkov (HAWC)...
One interesting class of models involves dark matter as the lightest state of a strongly interacting hidden sector, similar to the pions of QCD. In this talk, I will examine the possibility that the lightest vector resonances of the hidden sector are nearby in mass and accessible within the current operating energy of fixed-target experiments. These states significantly modify processes in the...
The High Altitude Water Cherenkov (HAWC) gamma-ray observatory is a wide field-of-view observatory sensitive to 0.5 TeV - 100 TeV gamma-rays and cosmic-rays in the State of Puebla, Mexico at an altitude of 4100m. The HAWC observatory performed an indirect search for dark matter via GeV-TeV photons resulting from dark matter annihilation and decay considering various sources, including 15 dwarf...
It is widely accepted that supernova (SN) shocks can accelerate particles to very high energies, although the maximum energies are still unclear. These accelerated particles can interact with other particles to produce gamma-ray emission. Details of the process are not well characterized, including the dynamics and kinematics of the SN shock wave, the nature and magnitude of the magnetic...
The Fermi Gamma-ray Burst Monitor (GBM) is an all-sky monitoring instrument sensitive to energies from 8 keV to 40 MeV. Over the past 8 years of operation, the GBM has detected over 240 gamma-ray bursts per year and provided timely GCN notices with localization to few-degree accuracy for follow-up observations. In addition to GRBs, Galactic transients, solar flares, and terrestrial gamma-ray...
In this talk we discuss the sensitivity of probing light bosons in the Borexino-SOX experiment, and the possibility of detecting heavy leptons in the SHiP and DUNE experiments.
Bringing an external radioactive source close to a large underground detector can significantly advance sensitivity not only to sterile neutrinos but also to "dark" gauge bosons and scalars. Here we address in detail...
Using a simplified model for the hadronic emission from young supernova remnants (SNRs), we derive an expression to calculate the hadronic luminosity with time, depending on the supernova (SN) ejecta density profile and the density structure of the surrounding medium. We then use this to estimate the gamma-ray emission from SN 1987A, the nearest visible supernova to us in over 300 years. The...
In the current understanding of structure formation in the Universe, the Milky Way is embedded in a clumpy halo of dark matter (DM). Regions of higher DM density are expected to present an enhanced rate of annihilation into gamma-rays with respect to the smooth halo regions. These point-like gamma-ray fluxes can possibly be detected by gamma-ray observatories on Earth, like the forthcoming...
Nanosecond precision timing synchronization via the Global Positioning System has become a common technique for a variety of particle physics and astrophysics experiments including, for example, large arrays of detectors for cosmic ray air showers. By using the common time-standard in GPS, time synchronization can be achieved at low cost, even over large areas in remote locations. ...
We present the results of an archival coincidence analysis between
public gamma-ray data from the Fermi LAT satellite and public
neutrino data from the IceCube neutrino observatory during its
40-string and 59-string observing runs. The analysis has the
potential to detect either a statistical excess of correlated
neutrino + gamma-emitting sources or alternatively, one or more
rare,...
The ANtarctic Impulsive Transient Antenna (ANITA) is a long-duration
balloon experiment with an interferometric radio payload. ANITA scans
Antarctic ice for Askaryan radio emission from interactions of
extremely-high-energy (>1 EeV) cosmogenic neutrinos. ANITA is also
sensitive to geomagnetic radio emission from extensive air showers
(EAS) initiated by both ultra-high-energy cosmic rays and...
Even when ultrahigh-energy (E > 10^10 GeV) cosmic rays (UHECRs) are heavy nuclei (with nuclear charge Z) as indicated by existing data, the pointing of cosmic rays to the nearest extragalactic sources (distance D) at highest energies remains expected, because the bending of the cosmic ray goes as BZD/E (B is the extra-galactic magnetic field). In addition, the acceleration capability of the...
The Antarctic Impulsive Transient Antenna (ANITA) is a NASA long-duration balloon experiment
with the primary goal of detecting ultra-high-energy ($>10^{18}\,\mbox{eV}$) neutrinos via the Askaryan Effect.
The fourth ANITA mission, ANITA-IV, recently flew from Dec 2 to Dec 29, 2016.
The most significant change in signal processing in ANITA-IV from previous flights was the inclusion of the...
A direct measurement of the gravitational acceleration of antimatter has never
been performed to date. Recently, such an experiment has been proposed, using antihydrogen with an atom interferometer and an Antihydrogen confinament has been realized at CERN. In alternative we propose an experimental test of the gravitational interaction with antimatter by measuring the branching fraction of the...
Recently many observational facilities have entered in their operational phase or they will approach the design sensitivity in the nearest future, allowing us to observe the universe with very high energy photons, cosmic rays, neutrinos and gravitational waves.
The MAGIC observatory: a system of two Imaging Atmospheric Cherenkov Telescopes located at the Canary Island of La Palma, thanks to...
The arrival directions of multi-TeV cosmic rays show significant anisotropies at large and small angular scales. I will argue that these features can be understood from standard cosmic ray diffusion. It is well-known that a large-scale dipole anisotropy is expected from a cosmic ray density gradient following the distribution of Galactic sources. However, the observed anisotropy depends on...
ANITA is a NASA balloon-borne radio (200-1200 MHz) telescope with a primary goal of detecting coherent radio emission from ultra-high-energy (UHE) neutrinos. The instrument is also sensitive to detect radio impulses produced by cosmic ray induced extensive air showers. ANITA-4 flew Dec 2, 2016 and landed Dec 29, 2016 after 28 days.
This talk will present the ANITA-IV instrument, flight...
The direct detection, for the first time, of gravitational wave (GW) transients by Advanced LIGO has motivated searches for their electromagnetic counterparts at all wavelengths. Neutrino astronomy is an emerging area of study in high-energy astrophysics, and astrophysical neutrinos are natural cousins of very high energy (VHE; E > 100 GeV) gamma rays. The VERITAS gamma-ray observatory has an...
In the minimal left-right symmetric model which could accommodate the tiny neutrino masses via TeV seesaw mechanism, the neutral scalar from the right-handed symmetry breaking sector could be much lighter than the electroweak scale. Limited by the meson oscillation and decay data, such a light particle is necessarily long-lived and decays predominantly into two photons, mediated by the heavy...
The current generation of Cherenkov telescopes, together with Fermi-LAT, has greatly improved our knowledge of blazar physics, providing a precise measurement of their gamma-ray emission. The modeling of multi-wavelength spectral energy distributions of blazars has been proven to be a unique tool to constrain and refine blazar emission models, and thus the physics of outflows from...
The shape of the large-scale cosmic-ray (CR) anisotropy depends on (and therefore contains information on) the local interstellar turbulence within ~ 10 pc from Earth. We calculate the TeV-PeV CR anisotropies predicted for a range of Goldreich-Sridhar (GS) and isotropic models of interstellar turbulence, and compare them with IceTop and IceCube data. The narrow deficits in the 400TeV and 2PeV...
The Askaryan Radio Array (ARA) is a gigaton, ultra-high energy (>10 PeV) radio neutrino detector under construction at South Pole; it searches for the characteristic radio Cherenkov pulses that are produced by neutrino interactions in the dense polar ice. The array has deployed three of the proposed ~37 stations so far, at depths up to 200m. In this talk, we will summarize the current status...
We test the hypothesis that blazars are sources of Ultra-High Energy Cosmic Rays (UHECR), considering acceleration of isotopes heavier than Hydrogen. We perform numerical simulations of CR interactions using the NeuCosmA code. The injected isotope may efficiently disintegrate at high energies, thus producing a population of lighter secondaries. We study the ejected CR composition and neutrino...
Tidal disruption events (TDEs) by supermassive or intermediate mass black holes have been suggested as candidate sources of ultrahigh-energy cosmic rays (UHECRs) and high-energy neutrinos. Motivated by the recent measurements from the Pierre Auger Observatory, which indicates a metal-rich cosmic-ray composition at ultrahigh energies, we investigate the fate of UHECR nuclei loaded in TDE jets....
Despite the recent discovery of the Higgs boson contributing to the success of the Standard Model, the large excess of dark matter in the Universe remains one of the outstanding questions in science. This excess cannot be explained by Standard Model particles. A compelling hypothesis is that dark matter is comprised of particles can be produced at the LHC, called Weakly Interacting Massive...
While constraints on primordial black holes as dark matter are strong over a wide mass range, a narrow window in the stellar-mass range remains relatively unconstrained. The recent discoveries of gravitational waves from merging black holes in roughly the 10-30 solar mass range has re-ignited the discussion of whether primordial black holes in this mass range could be a candidate for dark...
The Probe Of Extreme Multi-Messenger Astrophysics (POEMMA) mission is being designed to establish charged particle astronomy with ultra-high energy cosmic rays (UHECRs) and to observe astrophysical and cosmogenic neutrinos using both fluorescence and Cherenkov emission from extensive air-showers (EAS). The POEMMA design combines the concept developed for the Orbiting Wide-field...
Supernova 1987A provides strong constraints on hidden-sector particles with masses below ~100 MeV. If such particles are produced in sufficient quantity, they reduce the cooling time of the supernova, in conflict with observations. We consider the resulting constraints on dark photons, milli-charged particles, and sub-GeV dark matter coupled to dark photons. For the first time, we include the...
There is tentative evidence for an ultra-high-energy cosmic-ray (UHECR) “hot spot” coming from the direction of Centaurus A and also evidence for another hot spot that might be associated with the M81 group. Although the evidence is not firmly established, it is not all unreasonable, given the energetics and the physical conditions in Cen A and in various galaxies in the M81 group, that these...
It has been a mystery that with ten orders of magnitude difference in energy, high-energy neutrinos, ultrahigh-energy cosmic rays, and sub-TeV gamma rays all present comparable energy injection rate, hinting an unknown common origin. Here we show that black hole jets embedded in clusters of galaxies may work as sources of all three messengers. By simulating the particle propagation in the...
Dark matter decays or annihilations that produce line-like spectra may be smoking-gun signals. However, even such distinctive signatures can be mimicked by astrophysical or instrumental causes. We show that velocity spectroscopy-the measurement of energy shifts induced by relative motion of source and observer-can separate these three causes with minimal theoretical uncertainties. The...
Dark matter can be sought in complementary experiments: direct detection, indirect detection and colliders all contribute to a comprehensive set of searches for weakly interacting massive particles (WIMPs). This talk underlines the searches for Dark Matter by the ATLAS experiment in the context of this complementarity, using models that include a mediator particle between SM and DM.
The era of precision cosmology has revealed that ~80% of the matter in the universe is dark matter. Two leading candidates, motivated by both particle and astro-physics, are Weakly Interacting Massive Particles (WIMPs) and axionlike particles (ALPs), both of which have distinct gamma-ray signatures. The Fermi Large Area Telescope (Fermi-LAT) Collaboration continues to search for WIMP and ALP...
Will cover searches for neutralinos and electroweakinos.
I will summarize the All-Sky Automated Survey for Supernovae (ASAS-SN), the first astronomical survey to observe the entire visible sky for bright optical transients on a nightly basis.
The ARIANNA experiment is designed to observe cosmogenic neutrinos with energies in excess of 10^16 eV. The design envisions a grid of over 1000 independent radio detector stations, using high-gain log-periodic dipole antennas just below the surface to measure the characteristic Askaryan radio pulses from particle cascades generated in the ice by these neutrinos. Spaced a kilometer apart, this...
The Giant Radio Array for Neutrino Detection (GRAND) aims at detecting ultra-high-energy extraterrestrial neutrinos via the extensive air showers induced by the decay of tau leptons created in the interaction of neutrinos under the Earth's surface. Consisting of an array of $\sim 10^5$ radio antennas deployed over $\sim 2\cdot 10^5\,\mbox{km}^2$, GRAND plans to reach, for the first time, a...
The AMS-02 experiment has recently released a new measurement of the cosmic-ray antiproton spectrum. Assuming that cold dark matter (CDM) is made of self-annihilating particles, the AMS-02 data can be used to constrain the annihilation cross section. It is known however that CDM structures itself on scales much smaller than typical galaxies. This structuring translates into a very large...
Several theories beyond the Standard Model predict the existence of high mass neutral or charged Higgs particles or BSM decay modes of the 125 GeV Higgs boson. In this presentation, the latest ATLAS results on searches for these particles will be discussed.
Local Radio galaxies (RGs) like Centaurus A are intensively discussed as the source of the observed Cosmic Rays above 3 EeV (UHECRs).
In this talk a first systematic study is presented where all observational features of the UHECRs, i.e. the energy spectrum, the chemical composition and the arrival directions, are used to draw severe constraints on the UHECR contribution from the local RGs (up...
Cosmogenic neutrinos produced by cosmic rays during propagation are expected to arrive at Earth in roughly equal ratios of electron, muon, and tau neutrinos. Due the cyclic regeneration of tau neutrinos and tau leptons, radio-based experiments are sensitive to the air showers produced by tau leptons emerging from the interaction of Earth-skimming tau neutrinos. We present a study of the...
