https://lbnl.zoom.us/j/94928022788?pwd=emVQWG1mTnhSbHVqekVuenk0VEVQZz09 Abstract: In this talk, I will discuss the motivation for considering an extra mesoscopic Dark Dimension of length l ~ 1 – 10 microns, taking into account theoretical and observational arguments. I will then talk about cosmological aspects of the Dark Dimension. In particular this scenario leads, by the universal coupling of the Standard Model sector to bulk gravitons, … Read More

https://lbnl.zoom.us/j/94928022788?pwd=emVQWG1mTnhSbHVqekVuenk0VEVQZz09 In the age of gravitational wave astronomy and direct black hole imaging, the possibility that some of the black holes in the universe have a primordial, rather than stellar, origin, and that they might be a non-negligible fraction of the cosmological dark matter, is quite intriguing. I will review the status of the field, describe search strategies and future … Read More

Title: Cosmology and UnificationAbstract: Precision measurements of primordial correlators in the CMB, Large Scale Structure, and 21-cm cosmology may contain “on-shell” imprints of extremely heavy particle physics, with masses at or even above the inflationary Hubble scale, via the remarkable inflationary mechanism(s) known as “cosmological collider physics”. I will describe new robust mechanisms for extending the energy-range and strength of such signals, … Read More

Title: S-matrix positivity without Lorentz invarianceAbstract: Positivity bounds on the S-matrix provide powerful constraints on effective field theories in flat space. Extending these results to cosmological backgrounds requires an understanding of the analytic structure of amplitudes in theories with broken Lorentz invariance. A paradigmatic example is provided by relativistic superfluids. We investigate the S-matrix in a UV complete model of relativistic superfluid: a complex scalar … Read More

https://lbnl.zoom.us/j/94928022788?pwd=emVQWG1mTnhSbHVqekVuenk0VEVQZz09 Title: Probing Dark Matter with Galactic Center White DwarfsAbstract: White dwarfs have long been considered as large-scale dark matter detectors. Owing to their high density and relatively large size, these objects can capture large amounts of dark matter, potentially producing detectable signals. In this talk, I will discuss new dark matter searches using the white dwarf population within the Milky Way’s … Read More

https://lbnl.zoom.us/j/94928022788?pwd=emVQWG1mTnhSbHVqekVuenk0VEVQZz09 Title: Building Dark Structure Before Big Bang NucleosynthesisAbstract: I present a novel mechanism for creating primordial black holes and MACHOs.   A heavy dissipative dark sector can come to dominate the universe, creating an early matter dominated era prior to Big Bang Nucleosynthesis (BBN).  At this time the dark matter can form halos which persist after the phase transition back to … Read More

https://lbnl.zoom.us/j/94928022788?pwd=emVQWG1mTnhSbHVqekVuenk0VEVQZz09

Title: Minimal Warm Inflation with the heavy QCD axion Abstract: Slow-roll inflation is a successful paradigm. However, even small couplings of the inflaton to other light fields can dramatically alter the dynamics and predictions of inflation. As an example, the inflaton can generically have an axion-like coupling to gauge bosons. Even relatively small couplings will automatically induce a thermal bath … Read More

https://lbnl.zoom.us/j/94928022788?pwd=emVQWG1mTnhSbHVqekVuenk0VEVQZz09

Title: Astrophysical Uncertainties in Dark Matter-Electron Scattering and How to Elude Them Abstract: In this talk, I will discuss how dark matter-electron scattering calculations depend on the underlying astrophysical model of the dark matter halo velocity distribution. I will give a brief review of the main astrophysical halo models and the measurements of their associated parameters. The predictions for dark … Read More