We perform high resolution simulations in a scenario where the Peccei-Quinn (PQ) symmetry is broken after inflation starting at the epoch before the PQ phase transition and ending at matter-radiation equality. We characterize the spectrum of primordial perturbations that are generated and comment on implications for efforts to detect axion dark…

Conventionally, the main focus for the cosmic evolution of our universe has been on descriptions in terms of particles: dark matter (DM) as massive particle, and dark radiation, if existing at all, in the form of massless or very light particle. In this talk, I will discuss a scenario where conformal field theory (CFT) plays a crucial role in…

Axion and Axion-like particles are fascinating dark matter candidates and a great effort has been devoted to their study, both theoretically and experimentally. 

In this talk I will discuss two different astrophysical searches. The first one consists in looking with radio telescopes for the spontaneous…

Recent work has introduced a correspondence between jets and natural languages. In this talk, I will review how machine learning, with this natural language processing point of view, is changing the way we are thinking about jets. First, I will describe a very effective model for classification and regression tasks…

In the next decade, improvements in the CMB and Large Scale Structure (LSS) measurements will make the universe an excellent laboratory for neutrino physics. Besides knowing the sum of neutrino masses, we can better answer questions about neutrino properties, such as how long the SM neutrinos can live? In this talk,…

The Milky Way halo is the brightest source of dark matter (DM) annihilation on the sky. Indeed, the strength of the Galactic dark matter signal can be greater than that expected from dwarf galaxies even in regions away from the Inner Galaxy. In this talk, I will demonstrate the promise of the Milky Way halo, until now less focused on in the…

The properties of the smallest gravitationally-bound dark matter structures can be affected by non-trivial particle physics within the dark sector, and thus could provide the first hints of the non-gravitational interactions of dark matter. As our knowledge of Galactic stellar kinematics grows, we are discovering streams and debris consistent…

The most pressing fine-tuning puzzles of the Standard Model — the cosmological constant and weak hierarchy problems, as well as the Higgs metastability —  can all be understood as problems of near criticality. I will present a natural selection mechanism based on search optimization on the string landscape. The…

It has been recently pointed out that variable weak gravitational lensing effects on the motion of background stars can be used to probe nonluminous structures inside the Milky Way halo. I will describe one possible detection strategy targeting collapsed dark matter structures in the mass range from million to…

The observed flattening of rotation curves is usually considered strong evidence for the existence of dark matter on galactic scales.   However, observations such as the Baryonic Tully-Fisher Relation and the Radial Acceleration Relation suggest that the observed dynamics in galaxies are strongly correlated with the distribution of baryonic…

Detecting light dark matter that interacts weakly with electromagnetism has recently become one of the benchmark goals of near-term and futuristic direct detection experiments. In this talk, I will discuss an alternative approach to directly detecting such models below the GeV-scale, leveraging on the recent…

I discuss ways in which we might make very precise measurements of the dark matter in the Milky Way using kinematic and composition data on stars from the ESA Gaia Mission and spectroscopic surveys like SDSS-IV and -V. I will show two methods that outperform traditional methods (eg, using the Jeans equations), one…

Pulsars act as accurate clocks, sensitive to gravitational redshift and acceleration induced by transiting clumps of matter. We study the sensitivity of pulsar timing arrays (PTAs) to single transiting compact objects, focusing on primordial black holes and compact subhalos in the mass range from 10−12 Msun  to well above 100 M sun. We find…

There is a substantial effort in the physics community to search for dark matter interactions with the Standard Model of particle physics. Collisions between dark matter particles and baryons exchange heat and momentum in the early Universe, enabling a search for dark matter interactions using cosmological…

A stable sexaquark is an appealing Dark Matter candidate.   Simple statistical physics arguments, plus known QCD parameters (quark masses and QCD transition temperature), predicts the DM to baryon ratio after the QGP-hadron transition to be ~4.5 +- 1,  in remarkable agreement with the observed value of  5.3 +- 0.1. …

Abstract: The Galactic Center GeV Excess (GCE) is firmly detected. While there is statistical evidence suggesting the excess originates largely from point sources, its interpretation as a signal of annihilating dark matter has not been conclusively ruled out. In this talk, I will examine the impact of unmodelled source populations on…

ABSTRACT

More than 40 years after its theoretical description, the process of coherent elastic neutrino-nucleus scattering (CEvNS) has been observed for the first time by the COHERENT Collaboration, using a 14.6-kg CsI[Na] detector at the Spallation Neutron Source of Oak Ridge National Lab…

Abstract: Pure wino dark matter, transforming as a triplet under the SU(2) group of the Standard Model, provides an illustrative example of heavy weakly-interacting dark matter that is not yet excluded by direct and collider searches. The most stringent constraints on wino dark matter come from astrophysical searches for…

Abstract: Hidden sectors are motivated by a range of phenomena unexplained by the Standard Model, such as dark matter, neutrino masses, and the baryon asymmetry. Hidden sector particles below the weak scale can be copiously produced at high-energy and intensity-frontier experiments, but may have evaded detection with current searches. I will…

Abstract:  A well-motivated class of dark matter candidates, including axion-like particles and dark photons, takes the form of coherent oscillations of a light bosonic field. If the dark matter couples to Standard Model photons, it may be possible to detect it via absorptions in a laboratory target. I will discuss a new class of detectors at…