05 - Dark matter: 05 - Dark matter
- Marco Cirelli (CEA/Saclay)
05 - Dark matter
- Marco Cirelli (CEA/Saclay)
05 - Dark matter
- Marco Cirelli (CEA/Saclay)
Wing To (SLAC)
12/16/15, 2:00 PM
The Large Underground Xenon (LUX) project is a direct dark matter detection experiment using a dual-phase Xenon time projection chamber. The analysis has been improved for the first 90 live days of 2013 data while LUX collects another 300 live days of exposure. The enhancements include photon counting of S1, total charge measurements of S2, more calibration data, new background and signal...
Achim Gütlein (Austrian Academy of Sciences)
12/16/15, 2:25 PM
CRESST-II is a direct dark matter search using cryogenic detectors based on calcium tungstate. Due to their light nuclei and low energy thresholds these detectors allow for a high sensitivity for dark-matter particles with low masses. We present data corresponding to an exposure of 52 kg-days obtained by one single detector module with a very low energy threshold of 307 eV for nuclear...
Vivian Poulin (Unite Reseaux du CNRS (FR))
12/16/15, 2:45 PM
Cosmology, and especially the CMB anisotropies, has been proved to be a powerful tool in the quest for pinning down the nature of Dark Matter (DM). In this talk, I will review how it is possible to get very competitive constraints on the lifetime and the fraction of unstable DM particles, as well as constraints on the annihilation cross section, using either purely gravitationnial...
Sam Young (University of Sussex)
12/16/15, 3:05 PM
There are strong theoretical arguments which suggest that primordial black holes (PBHs) may have formed from the collapse of large over-densities during the radiation dominated epoch shortly after the end of inflation. Because these black holes can form on much smaller scales than those visible from the CMB or large-scale structure, they have historically been used to place a unique constraint...
Jens Niemeyer (Goettingen University)
12/16/15, 3:25 PM
Light scalar fields such as ultra-light axions (ULAs) are dark matter candidates which suppress the growth of perturbations on scales below their de Broglie wavelength and predict solitonic halo cores owing to their quantum pressure support. They therefore give rise to new phenomenology in large-scale structure formation and galaxy evolution, including a potential solution to the cusp-core and...
Dr Johann Cohen-Tanugi (LUPM, Université de Montpellier & CNRS/IN2P3)
12/16/15, 4:15 PM
Indirect dark matter (DM) searches rely on detection of stable by-products of DM interactions to search for a signal of this elusive component of the Universe. Among these final products, gamma rays have recently played a major role in understanding the nature of the DM particle. This contribution reviews the current status of indirect DM searches with the Large Area Telescope, the main...
Emmanuel Moulin (CEA Saclay)
12/16/15, 4:40 PM
The Cherenkov Telescope Array (CTA) is a worldwide project aiming at building the next ground based gamma-ray observatory with a sensitivity ten times better than current experiments like H.E.S.S., MAGIC and VERITAS. CTA will be composed of several tens of telescopes with different sizes distributed on two sites located in the northern and southern hemispheres. CTA will also have a much wider...
Hamish Clark (University of Sydney)
12/16/15, 5:05 PM
In this talk I will discuss recent efforts to detect dark matter 'ultracompact minihalos' (UCMHs), including a novel utilisation of gravitational time-delay lensing with pulsars. Recently proposed as a type of small-scale dark matter structure, UCMHs are formed from large overdensities in the very early Universe. They have been shown to be able to persist through to the present day, providing...
Andrea Vittino (Universita' di Torino and INFN Torino)
12/16/15, 5:30 PM
Antideuterons can be produced through the nuclear coalescence of the antiprotons and the antineutrons that are originated in a dark matter pair annihilation or decay event. At low kinetic energies, the fluxes of these bound states are found to dominate over the astrophysical background and thus antideuterons may be considered as a very promising channel for a dark matter indirect detection,...
Mathieu Boudaud (LAPTh Annecy France)
12/16/15, 5:50 PM
Using the updated proton and helium fluxes just released by the AMS-02 experiment we reevaluate the secondary astrophysical positron and antiproton fluxes. We compare our results with the positron flux and the preliminary antiproton to proton ratio, both measured by AMS-02. The main uncertainties for the theoretical calculation are assessed. For positrons, we test the possibility to explain...
Michael Kachelriess (NTNU)
12/16/15, 6:10 PM
I review the results of a new calculation for the antiproton production by cosmic ray protons and nuclei and discuss the expected theoretical uncertainty. Then I discuss the antiproton flux expected from a local, 2 Myr old SN and the implication for indirect dark matter searches.
Bhawna Gomber (University of Wisconsin (US))
12/16/15, 6:30 PM
LZ is a second-generation dark-matter experiment designed to achieve unprecedented sensitivity to weakly interacting massive particles (WIMPs) of masses from a few GeV/c to hundreds of TeV/c2. With total liquid xenon mass of about 10 tonnes, LZ is planned to achieve a sensitivity to WIMP-nucleon spin-independent cross section approaching ∼2⋅10−48 cm2 in 3 years of operation. This represents an...
Hyerim Noh (Korea Astronomy and Space Science Institute)
12/16/15, 6:33 PM
We show that the axion as a coherently oscillating scalar field acts as a cold dark matter (CDM) to the second-order perturbations in all cosmological scales including the super-horizon scale. The proof is made in the axion-comoving gauge. For a canonical mass, the axion pressure term causes deviation from the CDM only on scales smaller than the Solar System size. Beyond such a small scale the...
292. Indirect Dark Matter searches with the ASTRI mini-array in the framework of the Cherenkov Telescope Array
Dr Saverio Lombardi (OAR-INAF, ASDC)
12/16/15, 6:36 PM
Nowadays there are compelling evidences at several astrophysical scales for a large (~85%), dark, non-baryonic and non-relativistic component of the matter density of the Universe. The quest to explain the nature of Dark Matter (DM) represents a paramount issue of modern fundamental physics and astrophysics. The non-baryonic DM is compatible with a gas of cold and weakly interacting massive...
Dragan Hajdukovic (Institute of Physics, Astrophysics and Cosmology (ME))
12/16/15, 6:39 PM
We show that if quantum vacuum fluctuations are virtual gravitational dipoles, then the phenomena usually attributed to hypothetical dark matter, may be considered as a consequence of the gravitational polarization of the quantum vacuum by the immersed baryonic matter; apparently, at least mathematically, the galactic halo of dark matter can be replaced by the halo of the polarized quantum...
Sinziana Paduroiu (University of Geneva)
12/16/15, 6:42 PM
Using cosmological simulations we explore the effects of warm dark matter (WDM) particles (e.g. sterile neutrinos)on the structure formation for different mass particles. Properties like the velocity dispersion and the damping of the fluctuation spectrum imprint a distinct signature on the structure formation mechanism as well as on the evolution of structures and on the internal structure of...
Jeroen Franse (Leiden University)
12/17/15, 2:00 PM
The latest observational status of the candidate dark matter decay signal at 3.5 keV will be presented. This unidentified X-ray line is observed in multiple galaxies and galaxy clusters. Instrumental effects or plasma emission are disfavoured while the observations are consistent with a decaying dark matter interpretation. In addition to a review of the existing work, the latest developments...
David Richard Harvey (EPFL - EPF Lausanne)
12/17/15, 2:21 PM
Recent studies into the dynamics of galaxy clusters and galaxy cluster members have revealed potential signatures of self-interacting dark matter. In this talk I will discuss the current evidence that supports this hypothesis and the observational signals that self-interacting dark matter may manifest itself as. I will finish by presenting current work and observations from the worlds best...
Thomas David Jacques (Universite de Geneve (CH))
12/17/15, 2:42 PM
WIMPs with suppressed interactions can present observational challenges at lowest order. We study Majorana DM interacting via an axial-vector Z’, where both the self-annihilation rate and WIMP-nucleon scattering rate are suppressed. By including loop diagrams in the calculation of the self-annihilation rate, we find that the self-annihilation rate is notably enhanced relative to the tree-level...
Mikhail Ivanov (Ecole Polytechnique Federale de Lausanne (CH))
12/17/15, 3:03 PM
Baryon acoustic oscillations (BAO) provide us with one of the most powerful cosmological probes. However, the BAO are plagued by non-linear effects which must be taken into account. I will discuss these effects and their physical impact on correlation functions in real and momentum spaces. I will present a new technique (so-called 'IR — resummation') to account for these effects to all orders...
Dr Adam Amara (ETHZ - ETH Zurich)
12/17/15, 3:24 PM
The Dark Energy Survey (DES) is a 5000 square degree survey targeting dark matter and dark energy science. This year sees the release of the first science results from the DES collaboration using data taken during science verification. I plan to present these new results, which include dark matter maps, cosmology constraints and new discoveries such as the new strong lens systems being found....