Abstract:  Dark matter could be a thermal relic of freeze-in, where the dark matter is produced by extremely feeble interactions with Standard Model particles dominantly at low temperatures. The simplest sub-MeV dark matter models with freeze-in include models with a kinetically-mixed dark photon mediator, or equivalently models where dark…

Abstract:  In this talk, I will explore two recent developments in the search for dark matter. First, I will discuss how the 21-cm global signal measurement constrains the potential impact of dark matter annihilation/decay on the thermal history of the universe. I will also explain how to accurately compute such modifications to the baryon…

Abstract:  Conformal Field Theories (CFTs) have a highly constrained structure that make them much more tractable, especially at strong coupling, than generic QFTs.  An appealing picture for more general QFTs is as points along the RG flow from a UV CFT.  We discuss conformal truncation as a method for nonperturbatively following such RG flows…

Upcoming sensor technology allows for dark matter direct detection all the way down to the warm dark matter limit of ~ 10 keV. At such low masses, the usual nuclear recoil picture breaks down, as the dark matter recoils against athermal phonon modes instead. I will show how the rate for these processes can be calculated and why superfluid…

The central region of Supernovae are one of the hottest and densest regions in the Universe. Due to the high temperatures, particles with sub-GeV masses can be copiously produced if they have non-negligible couplings to the Standard Model. If dark matter has sub-GeV mass it will be produced in the hot Supernovae core and it will have…

In this talk, I will provide an introduction to an alternate framework for dark-matter physics which we call "Dynamical Dark Matter" (DDM).  Within this framework, the requirement of dark-matter stability is replaced by a balancing of lifetimes against cosmological abundances across an ensemble of individual dark…

The Axion Dark Matter eXperiment (ADMX) is a DOE "Generation 2" direct-detection dark matter project searching for the resonant conversion of axions to photons in a tunable, high-Q microwave cavity surrounded by a strong magnetic field. Over the last decade, ADMX has undergone multiple upgrades and is now operating…

Neutrinos and other light relic particles leave a number of imprints in the cosmic microwave background anisotropies and on maps large-scale structure of the universe. Some of these imprints can not only demonstrate the presence of these particles, but can provide insight into their nature via signatures of interactions or other behavior that…

In the first part of this talk, I will discuss how we can use observations of the Cosmic Microwave Background and the Large-Scale Structure of the universe to improve our understanding of an open question in fundamental physics: the particle nature of dark matter. I will review my work aimed at identifying…

 An important part of the LHC legacy will be precise limits on indirect effects of new physics, parameterized for instance in an Effective Field Theory (EFT). These measurements involve many parameters and observables and are often challenging for established analysis methods. We explain the structure of this “likelihood-free” inference problem…

Abstract:  Two pivotal breakthroughs in physics recently turned respectable centennials: the discovery of the Schwarzschild solution, describing a non-rotating black hole, and Einstein's prediction of gravitational waves.  Gravitational waves offer a unique glimpse into the unseen universe, and allow us to test the basic tenets of General…

Abstract:   Wouldn't it be lovely if we could use the same variational approaches familiar from quantum mechanics to study quantum field theories? We can, of course; the real question is how do we do this efficiently? In this talk I will discuss the recent revival of approximate Hamiltonian diagonalization as a means to numerically study field…

Abstract:  Strong lensing is a sensitive probe of the small-scale density fluctuations in the Universe. We implement a pipeline to model strongly lensed systems using probabilistic cataloging, which is a transdimensional, hierarchical, and Bayesian framework to sample from a metamodel (union of models with different dimensionality) consistent…

Abstract:  : While the current vacuum energy of the Universe is very small, in our standard cosmological picture it has been much larger at earlier epochs. We try to address the question of what are possible ways to try to experimentally verify the properties of vacuum energy in phases other than the SM vacuum. One promising direction is to…

Abstract:  Using the hydrodynamic simulation Eris, as well as various realizations of the Milky Way from the FIRE simulation, we found that the kinematics of dark matter follows closely the kinematics of old metal poor stars. We use this correspondence to obtain the first empirical measurement of the local velocity distribution of dark matter,…

Abstract:  I will discuss how we can probe the early universe through studying the properties of the Higgs.  I will also demonstrate how the early universe can have a different phase history than is typically assumed.  Additionally, I will demonstrate how thermal resummation techniques can be used to study the early universe more accurately. 

Abstract:  I explore the cosmological signatures associated with the twin baryons, electrons, photons and neutrinos in the Mirror Twin Higgs framework. I consider a scenario in which the twin baryons constitute a subcomponent of dark matter, and the contribution of the twin photon and neutrinos to dark radiation is suppressed due to late time…

Abstract:   New physics has traditionally been expected in the high-pT region at high-energy collider experiments. If new particles are light and weakly-coupled, however, this focus may be completely misguided: light particles are typically highly concentrated within a few mrad of the beam line, allowing sensitive searches with small detectors,…

Abstract:  The absence of sizeable CP violation in the strong sector is a long standing puzzle. A class of solutions to this problem rely on a global U(1) symmetry that is anomalous with QCD. These solutions lead to robust low-energy predictions, for example a massless up quark or a light axion. I will present simple extensions to such…

Abstract:  A typical new physics search by CMS can now have hundreds of exclusive signal regions. While this has the potential for great discriminating power, it can also obscure potentially interesting discrepancies if they do not occur in the handful of signal regions that are probed by a small set of simplified models used by the analysis…