Ultralight bosonic particles, including axionlike particles and kinetically mixed dark photons, can be promising dark matter candidates. It was recently shown that the Earth can act as a transducer for ultralight dark matter detection, by converting the dark matter into an oscillating monochromatic magnetic field signal across the Earth's surface. This occurs because the ground and ionosphere...
We revisit the framework of axion-like inflation, considering a warm inflation scenario in which the inflaton couples to the topological charge density of non-Abelian gauge bosons whose self-interactions result in a rapidly thermalizing heat bath. Including both dispersive (mass) and absorptive (friction) effects, we find that the system remains in a weak regime of warm inflation (thermal...
Motivated by the direct discovery of gravitational waves (GWs) from black holes and neutron stars, there is a growing interest in investigating GWs from other sources. Among them, GWs from cosmic strings are particularly fascinating since they naturally appear in a large class of grand unified theories (GUTs). Remarkably, a series of pulsar-timing arrays (PTAs) might have already observed GWs...
Inflationary models, especially those with plateau-type potentials, are consistent with the cosmological data, but inflation itself does not resolve the initial singularity. This singularity is resolved, for example, by the idea of the quantum creation of the Universe from nothing such as the tunneling and no-boundary proposals. The simplest one predicts a closed Universe. Motivated by these...
The current best limits on properties of potential particle physics candidates for dark matter are set by direct dark matter detectors using high purity liquid xenon. XENONnT, with 5.9 tonnes of instrumented liquid xenon, was commissioned in the middle of 2021, and completed its first science run in 2022. This talk will present the results of the first science run of XENONnT.
The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment searching for $0\nu\beta\beta$ decay that has been able to reach the one-tonne mass scale. The detector, located at the LNGS in Italy, consists of an array of 988 TeO$_2$ crystals arranged in a compact cylindrical structure of 19 towers. CUORE began its first physics data run in 2017 at a base...
In light of the recent swampland conjectures, we explore quantum cosmology and eternal inflation beyond the slow roll regime. We consider a model of a closed universe with a scalar field $\phi$ in the framework of tunneling approach to quantum cosmology. The scalar field potential is assumed to have a maximum at $\phi=0$ and can be approximated in its vicinity as $V(\phi)\approx...
We derive consistency conditions for sustained slow roll and rapid turn inflation in two-field cosmological models with oriented scalar field space, which imply that inflationary models with field-space trajectories of this type are non-generic. In particular, we show that third order adiabatic slow roll, together with large and slowly varying turn rate, requires the scalar potential of the...
We study the gravitational wave signals of ultralight axion dark matter around Kerr black hole by LISA in synergy with SKA.
In coherent elastic neutrino nucleus scattering (CE$\nu$NS), the neutrino interacts with the nucleus as a whole. This leads to a tiny recoil that can be registered with suitable detector technologies. The detection is highly challenging and requires a neutrino source within the coherent energy regime such as a nuclear power plant, a low enough energy threshold of the detectors and an excellent...
Big ideas and powerful instruments have allowed us to reconstruct the history of universe from its big-bang beginning 13.8 billion years ago through an early state of quantum fluctuations to a soup of quarks and other particles, from the formation of nuclei and atoms to the emergence of stars and galaxies, and finally to its accelerating expansion today driven by dark energy. I will share what...
As a black hole tends towards maximal spin the near-horizon region develops a throat-like geometry of divergent proper volume. The development of this throat has consequences on observable phenomena. Herein we will examine two such examples. First we consider adiabatic growth of a black hole within a cloud of particles. For a high-spin black hole this process results in a finite nonzero...
We present a model that explains the origin of the neutrino mass ordering through the spontaneous breaking of a discrete flavor symmetry. Our model addresses the hierarchy between neutrino masses by combining the seesaw and scotogenic mechanisms, both emerging naturally from an $A_4$ discrete symmetry broken at the electroweak scale. The model incorporates a scalar dark matter particle...
We demonstrate that the Higgs boson mass can be extracted from the dispersion relation obeyed by the correlation function of two b-quark scalar currents. The solution to the dispersion relation with the input from the perturbative evaluation of the correlation function up to next-to-leading order in QCD and with the $b$ quark mass $m_b=4.43$ GeV demands a specific Higgs mass $115^{+13}_{-9}$...
We discuss a unified model that solves four major problems of the standard model i.e. neutrino masses the origin of matter the strong CP problem and dark matter by using the framework of the Affleck-Dine (AD) mechanism. The AD field is responsible for inflation the origin of matter and neutrino masses which arise at the one-loop level. Neutrino masses are therefore intimately...
An electroweak-charged dark matter Model a well-motivated dark matter candidate. The Wino, Higgsino and 5plet fermions are typical examples.
In these models, the charged partner becomes metastable.
Disappearing charged tracks and soft objects produced by the charged partner are important for the test of this model in collider experiments.
The signals strongly depend on the lifetime and...
The existence of supermassive black holes at the center of galaxies redistributes the dark matter density profile in the region of influence and creates a higher density region so-called density spike. In the self-interaction dark matter scenario, the velocity dispersion in the spike region scales with a power law of r^−1/2, and the density spike scales with a power law of r^−(3+a)/4, where...
DarkPACK is a software that automatically generates a numerical library
of scattering amplitudes from the Lagrangian density of the model, to
compute dark matter observables such as relic density. It relies on
MARTY and SuperIso relic and is written in C++. In the current
version, DarkPACK can easily generate all the squared
amplitudes of 2 NP particles into 2 Standard Model...
The “electroweak dumbbell” consists of a magnetic monopole and an antimonopole of the standard electroweak model connected by a string made of Z-magnetic field. The dumbbells formed during the epoch of electroweak symmetry breaking in the early Universe undergo annihilation, and leave behind cosmological relic magnetic fields. Electroweak dumbbells may also be produced in scattering...
The ability to represent perturbative expansions of interacting quantum field theories in terms of simple diagrammatic rules has revolutionized calculations in particle physics. However in the case of extended theories of gravity deriving this set of rules requires linearization of gravity perturbation of the scalar fields and multiple field redefinitions making this process very...
We study the possibility of measuring neutrino Yukawa couplings in the Next-to-Minimal Supersymmetric Standard Model with right-handed neutrinos (NMSSMr) when the lightest right-handed sneutrino is the Dark Matter (DM) candidate by exploiting a `dijet + dilepton + Missing Transverse Energy' (MET or $\slashed{E}_T$) signature. We show that this extended model of SUSY offers a much lighter...
Under certain assumptions and independent of the instantons, we show that the
logarithm expansion of dimensional regularization in quantum field theory needs a
nonperturbative completion to have a renormalization-group flow valid at all ener-
gies. Then, we show that such nonperturbative completion has the analytic proper-
ties of the renormalons, which we find with no reference to...
Very light pseudoscalar fields, often referred to as axions, are compelling dark matter candidates and can potentially be detected through their coupling to the electromagnetic field. Recently a novel detection technique using the cosmic microwave background (CMB) was proposed, which relies on the fact that the axion field oscillates at a frequency equal to its mass in appropriate units,...
Left-Right (LR) theories are one of the successful beyond Standard Model (SM) frameworks that explain the origin of small neutrino masses and low-energy weak parity violation. However, the conventional LR theory faces a challenge due to the presence of flavor changing neutral currents (FCNCs). To address this, we have studied an Alternative LR model (ALRM), which avoids FCNC constraints. Our...
I will discuss ongoing work in studying how the combination of two modified gravity theories that are well motivated from string theory, Dynamical Chern-Simons (dCS) and Einstein-dilaton-Gauss-Bonnet (EdGB) gravity, will affect the gravitational waveforms emitted from a binary neutron star system, as well as observed neutron star relations such as the mass-radius relation and universal...
It has proven surprising difficult to obtain a microscopic understanding of Dark Energy within string theory. The two main paradigms, a landscape of de Sitter vacua or slow-roll quintessence, seem to require working at the boundaries of control, which has led to much fruitful debate. I will discuss alternative scenarios for Dark Energy within string theory, in which interacting Dark Sectors...
The gauge bosons of a hidden U(1) sector seems to be one of the simplest extensions of the standard model. However, if this hidden sector includes magnetic charges a host of novel phenomena result. These include new dark matter possibilities with distinctly new way to detect them. I give an overview of some of the phenomena and theoretical understanding that hidden magnetic monopoles provide.
Magnetic monopoles and dyons are unique beasts in the zoo of Quantum Field Theory. The long range interaction between monopoles and electric charges generates an extra electromagnetic angular momentum, fundamentally changing the S-matrix for their scattering.
Though the effective field theory of Dirac monopoles and charges has been known since the ‘70, its Hilbert space has only been...
In the last decade our understanding of holography has reached the point where a resolution of Hawking's black hole information problem seems to be in reach. In this talk I'll give a high-level overview of where we are now.
I will describe a unified mechanism for generating a baryon and dark matter asymmetry in models with multiple hidden sectors that are Standard Model-like but with varying Higgs mass parameters. These models have a unique cosmology with the different sectors reheated asymmetrically to relatively low temperature. A hidden sector with positive Higgs mass squared can accommodate dark matter with...
It is expected that any global symmetry is explicitly violated by gravity. In QCD axion models the effective axion potential obtains other terms than QCD contributions due to gravitational violation of the global U(1) Peccei-Quinn (PQ) symmetry and the minimum of the potential is deviated from the CP-conserving points. In general the deviation is large enough to invalidate the PQ solution...
Complex scalars in U(1)-symmetric potentials can form stable Q-balls, non-topological solitons that correspond to spherical bound-state solutions. If the U(1) charge of the Q-ball is large enough, it can support a tower of unstable radial excitations with increasing energy. Previous analyses of these radial excitations were confined to fixed parameters, leading to excited states with different...
Cachazo, He, and Yuan (CHY) demonstrated an alternative approach for computing the tree-level S-matrix of pure Yang-Mills theories in arbitrary spacetime dimensions on shell, as a contour integral encircling solutions of the so-called "scattering equations" in their paper "Scattering of Massless Particles in Arbitrary Dimensions." Later, Dolan and Goddard analyzed the scattering equations and...
Many scenarios of physics beyond the Standard Model predict new
particles with masses well below the electroweak scale. Low-energy, high
luminosity colliders such as BABAR are ideally suited to discover these
particles. We present several recent searches for low-mass dark sector
particles at BABAR, self-interacting dark matter, axion like particles,
and dark sector particles produced in B...
Among the numerous technologies developed in the field of Dark Matter direct detection, noble element dual-phase time projection chambers (TPC) have proved to be an outstanding solution, scalable to extremely high target masses without dramatic increases in read-out complexity. The DarkSide programme pioneered the use of liquid argon as a DM scattering target in such detectors and is now...
We explore possible mechanisms of suppressing the production of keV scale sterile neutrinos, which is the target parameter space of several current/upcoming laboratory experiments such as KATRIN, HUNTER or MAGNETO-nu. These alternative scenarios include universes with a nontrivial cosmic lepton number, new neutrino interactions with light bosons, late-time neutrino mass generation, low...
It is well-known that renormalizable theories of quadratic gravity pose a risk to unitarity of the S-matrix due to the spin-2 ghost degrees of freedom that they inevitably propagate. However, in recent years, a few promising methods to guarantee unitarity in the presence of these ghosts have been proposed. In light of these recent developments, we consider a generic model of quadratic gravity...
We study the cosmological signatures of a completely secluded dark sector consisting of axion-like particles (ALPs) with anomalous coupling to a dark Abelian gauge boson. The lighter ALP starts rolling during matter domination and produces dark photons through tachyonic instabilities. The resulting exponential growth in dark photon quanta sources tensor and scalar perturbations which are...
The impact of axion-like particles on the light polarization around the horizon of supermassive black hole (SMBH) is discussed in the light of the latest polarization measurement of the Event Horizon Telescope (EHT). We investigate different sources of the polarization due to axion interaction with photons and the magnetic field of SMBH. These can modify the linear and circular polarization...
Rotations of axion fields in the early universe can produce dark matter and matter-antimatter asymmetry of the universe.
In a class of models, the equation of state of the rotations rapidly changes from a non-relativistic matter-like one to a kination-like one.
We point out that the rapid change can produce an observable amount of gravitational waves through the Poltergeist mechanism.
The Standard Model effective field theory (SMEFT) is a standard tool for parametrizing the effects of new physics. The ordiinary approach to SMEFT is to use the truncation at dimension-6, which would typically be the leading contribution beyond the Standard Model. We perform the matching to dimension-8 in the two-Higgs-doublet model (2HDM) and critically examine the dimension-6 and dimension-8...
In the ever-expanding landscape of BSM model building, the ubiquitous presence of new vector bosons has led to new frontiers in probing the depths of fundamental physics. While it is widely acknowledged that non-conserved currents of these vector bosons can lead to (energy/vector mass)^2 enhancements, we diverge from standard literature and consider the realm of conserved currents. We...
In this talk, I will present a novel technique to search for axions with a CP-violating monopole coupling $\tilde{g}_{Q}$ to bulk SM charges $Q \in \{B,L,B-L\}$. Gradients in the static axion field configurations sourced by matter induce achromatic circular photon birefringence via the axion-photon coupling $g_{\phi \gamma}$. Circularly polarized light fed into an optical or (open)...
Axion-like dark matter whose symmetry breaking occurs after the end of inflation predicts enhanced primordial density fluctuations at small scales. This leads to dense axion minihalos (or miniclusters) forming early in the history of the Universe.
Condensation of axions in the minihalos leads to the formation and subsequent growth of axion stars at the cores of these halos. If, like the...
In this talk, I will motivate why in the 2020s so many of us are focusing on astrophysics and cosmology as an important tool for studying one of the most challenging questions in all of particle physics: determining what exactly dark matter is comprised of. I will focus most especially on questions relating to large-scale structure an axion-like particle models, as well as on asymmetric dark...
Solutions of the strong CP problem based on modular invariance are discussed in several frameworks.
Modular transformations of string theory are shown to play a crucial role in the discussion of discrete flavor symmetries in the Standard Model. They include CP transformations and provide a unification of CP with traditional flavor symmetries within the framework of the eclectic flavor scheme. The unified flavor group is non-universal in moduli space and exhibits the phenomenon of "Local...
Semi-realistic string models offer a plausible path to uncover the flavor structure of particle physics, which improves over models based on pure traditional or pure modular flavor symmetries. Interestingly, the eclectic flavor picture they exhibit, leads to realistic patterns of fermion masses and mixings, which depend on a modulus and matter-field configuration. Further, string models...
Dark matter particles can form halos gravitationally bound to massive astrophysical objects. The Earth could have such a halo where depending on the particle mass, the halo either extends beyond the surface or is confined to the Earth’s interior. We consider the possibility that if dark matter particles are coupled to neutrinos, then neutrino oscillations can be used to probe the Earth’s dark...
Rare kaon decays are among the most sensitive probes of both heavy and light new physics beyond the Standard Model description thanks to high precision of the Standard Model predictions, availability of very large datasets, and the relatively simple decay topologies. The NA62 experiment at CERN has reported the first observation of the ultra-rare $K^+\to\pi^+\nu\bar\nu$ decay, and is...
Abstract: Gravitational waves from cosmological phase transitions offer the chance to probe the very first second of the universe’s history and are one of our most promising signal channels of BSM physics. With space-based detectors such as LISA on the horizon, we urgently need reliable tools for predicting GW signals in strongly-coupled theories. In this talk, I discuss our recent proposal...
Indirect detection is one of the most powerful methods to search for annihilating dark matter (DM) covering a broad range of masses and interactions. Recently, non-perturbative effects have been shown to significantly alter model observables. In this work, we investigate the impact of non-perturbative effects in the indirect detection of DM. For this purpose we utilize a minimal model...
I will focus on the computation of graviton function in (Anti)-de Sitter space, specifically concentrating on gravitons with all positive external helicity. To tackle this problem, I will introduce a generalized recursion method inspired by the BCFW (Britto-Cachazo-Feng-Witten) technique. This method involves a deforming of the external momentum of the graviton function by complexifying it and...
The minimum testable dark matter (DM) mass for almost all DM signatures in celestial bodies is determined by the rate at which DM evaporates. DM evaporation has previously been calculated assuming a competition between the gravitational potential of the object, and thermal kicks from the celestial-body matter. I will point out a new effect, where mediators with a range larger than the...
The Kahler potentials of modular symmetry models receive unsuppressed contributions which may be controlled by a flavor symmetry, where the combination of the two symmetry types is referred to as eclectic flavor symmetry. After briefly reviewing the consistency conditions of eclectic flavor symmetry models, including those with generalised (g)CP, we perform a comprehensive bottom-up study of...
In this presentation, I discuss the production of a spectator scalar dark matter field that directly couples to the inflaton. Conventional scenarios of purely gravitationally produced dark matter with masses below the Hubble parameter at the end of inflation are in tension with Cosmic Microwave Background (CMB) constraints on the isocurvature power spectrum. We explore a more general scenario...
Modular flavor symmetries have gained significant attention as a promising method for predicting lepton mixing parameters. However, in a bottom-up approach, the lack of precise control over the parameters in the kinetic terms limits their predictability . To address this, we propose deriving the Yukawa couplings from an underlying geometry, specifically magnetized tori.
In this talk, we...
Pulsar timing array experiments aim to detect nHz-frequency gravitational waves using high-precision timing of millisecond pulsars. Of particular interest is a stochastic gravitational wave background (SGWB), which is expected to arise predominantly from a population of inspiraling supermassive black hole binaries, but there may also be contributions from exotic cosmological sources, such as...
FASER, the ForwArd Search ExpeRiment, is an LHC experiment located 480 m downstream of the ATLAS interaction point, along the beam collision axis. FASER and its sub-detector FASERnu have two physics goals: (1) to search for new light and very weakly-interacting particles, and (2) to detect and study TeV-energy neutrinos, the most energetic neutrinos ever detected from a human-made source....
FASER, the ForwArd Search ExpeRiment, is a currently operating experiment at the Large Hadron Collider (LHC) that can detect light long-lived particles produced in the forward region of the LHC interacting point. In this paper, we study the prospect of detecting light CP-even and CP-odd scalars at FASER and FASER 2. Considering a model-independent framework describing the most general...
Ultra-light axions with masses $10^{-33} < m_\phi/{\rm eV} < 10^{-22}$ are allowed to constitute only a small fraction of the observed dark matter abundance. Nevertheless, they may yet produce a visible impact on the cosmology due to their macroscopic quantum scale. Next generation galaxy survey data are poised to challenge this possibility, but in order to do so, all aspects of structure...
Primordial Black Holes (PBHs) may form in the early universe, from the gravitational collapse of large density perturbations, generated by large quantum fluctuations during inflation. Since PBHs form from rare over-densities, their abundance is sensitive to the tail of the primordial probability distribution function (PDF) of the perturbations. It is therefore important to calculate the full...
Restoration of left-right symmetry at high energy scales provides a well-motivated extension of the Standard Model, which has been scrutinized over the past few decades and that can be viewed as the intermediate step towards grand unification. In my talk, I will investigate whether these models can be probed via the search for a stochastic gravitational wave background induced by the...
If the PQ symmetry is broken after inflation then the QCD axion mass that gives rise to the observed dark matter (DM) abundance can in principle be calculated precisely. In practice it remains a computational challenge to accurately predict the DM contribution from nonlinear features of the PQ field such as axion strings, which introduce a large hierarchy of scales between their width and the...
