Abstract: Dark matter with mass below a GeV is invisible to standard WIMP searches. In this talk I will present two recent proposals for direct detection of keV-GeV mass dark matter, both utilizing Dirac materials, where low-energy electronic excitations have linear dispersion relations and obey the Dirac equation. Dark matter with mass in the MeV-GeV range can eject electrons from … Read More
Abstract: I will discuss two applications of Effective Filed Theory in the context of gravity. One is an EFT that allows us to parametrize what extensions of GR can be tested with gravitational wave observations. The most general action not involving additional degrees of freedom corresponds to adding to the GR Lagrangian operators constructed out of powers of the Riemann … Read More
Abstract: The early universe could feature multiple reheating events, leading to jumps in the visible sector entropy density that dilute both particle asymmetries and the number density of frozen-out states. In fact, late time entropy jumps are usually required in models of Affleck-Dine baryogenesis, which typically produces an initial particle-antiparticle asymmetry that is much too large. An important consequence of … Read More
Abstract: I will present a proposal for a new class of bosonic dark matter (DM) detectors based on resonant absorption onto a gas of small polyatomic molecules. Bosonic DM acts on the molecules as a narrow-band perturbation, like an intense but weakly coupled laser. The excited molecules emit the absorbed energy into fluorescence photons that are picked up by sensitive … Read More
Abstract: After an introduction to machine learning from the perspective of a theoretical physicist, I will describe a new method to perform a model independent search for new phenomena on data, with an emphasis on the LHC. I will discuss a systematic way to address the look-elsewhere effect and other issues that led similar attempts to fail rather spectacularly in … Read More
Abstract: New particles may be produced at the LHC with very high boost, for instance if they result from the decay of a heavier resonance. If these boosted particles decay hadronically then their signature is a single fat jet, perhaps with unusual substructure. I will discuss new techniques to search for such boosted resonances, whether their properties are predicted by … Read More