ABSTRACT: The search for dark matter substructure in strong lensing images is a technically highly challenging task. Challenges include the marginalization over an extremely large number of parameters and image regularization with non-trivial geometries, and are common to many data analysis tasks in astronomy and particle physics. In this talk, I will expose the significant limitations of traditional likelihood-based approaches. … Read More
Two critical problems are the origin of the baryon asymmetry and the nature of dark matter. In this talk, I will present a minimal, renormalizable model for baryogenesis in which both the dark and standard-model matter asymmetries originate from the same mechanism: electroweak-like baryogenesis in a dark “mirror” sector. In addition to outlining the model and the baryogenesis mechanism, this … Read More
Abstract: Null results from decades of collider, direct and indirect detection searches for DM have been eliminating regions of parameter space most natural for the minimal WIMP scenario. This has resulted in increased interest in non-minimal DM scenarios, spanning many orders of magnitude in mass, and a broad variety of interactions. In this talk I will explore how deviating from … Read More
Perturbative unitarity arguments are commonly used to derive, smilingly model independent, upper bound on a WIMP dark matter massl. In this talk I will present a new thermal, 2-to-2, freezeout mechanism which results in dark matter masses exceeding the unitarity bound by many orders of magnitude, without violating perturbative unitarity or modifying the standard cosmology.
Abstract: Under some conditions, light boson fields grow exponentially around a rotating black hole, called the superradiance instability. We discuss the effects of nonlinear interactions of the boson on the instability. In particular, we focus on the effect of the particle production and show that the growth of the boson cloud may be saturated much before the black hole spin … Read More
As the age of WIMP-scale dark matter (DM) draws to a close thanks to the ever-increasing sensitivity of direct detection experiments, the majority of sub-GeV DM parameter space remains to be explored. Sub-GeV DM can excite electronic transitions in a variety of molecular and nano-scale systems which have sub-eV scale thresholds. In particular, organic molecules and mesoscopic structures can be … Read More
I will present a framework for computing dark matter direct detection rates via phonon and magnon excitations in crystal targets for general dark matter models. It consists of parameterizing dark matter interactions by a nonrelativistic EFT, and computing material responses to the EFT operators. Our work extends previous calculations that focused on simple models such as standard spin-independent interactions, and … Read More
Abstract: Standard lore holds that a consistent theory of quantum gravity cannot have exact global symmetries. In this talk, we will show how simple generalizations of this lore can be used to motivate a number of other well-supported “Swampland conjectures,” thereby highlighting the importance of global symmetries for understanding universal features of quantum gravity. We remark briefly on possible consequences … Read More
4D Seminar: Kyohei Mukaida (CERN) “Leptogenesis from Axion Inflation”Abstract: In inflation models driven by an axion-like particle, the inflaton may have a Chern-Simons coupling to the Standard Model (SM) U(1)_Y. During inflation, this Chern-Simons coupling sources dual production of B+L asymmetry and maximally helical U(1)_Y gauge fields, associated with the SM chiral anomaly equation. In this talk, we will show … Read More
Abstract: I will discuss the cosmological (de)confinement phase transition (PT) of nearly conformal, strongly coupled large N field theories, applicable to composite Higgs models, using their holographic dual 5D formulation. In this description, the PT is from the high temperature phase in which the IR of the warped extra dimension is covered by a black-brane horizon to the low temperature … Read More