Talks

In this talk I will do three things. First, I will outline the conditions under which the interaction rate of inelastic processes with a system consisting of N targets scales as N^2. Second, I will present computations of interaction rates for several weakly interacting particles, including the Cosmic Neutrino Background and QCD axion dark matter, and will explain the underlying physics. Third, I will introduce new quantum observables that do not rely on net energy transfer, but can still extract these N^2 effects. This talk will not address a concrete experimental proposal, but the effects presented may point to a new class of table-top and ultra-low threshold particle detectors.

In this seminar, I will discuss recent progress towards developing robust methods to constrain PNG in the non-linear regime based on the LSS consistency relations — non-perturbative statements about the structure of LSS correlation functions derived from symmetries of the LSS equations of motion. Specifically, I will present non-perturbative models for the squeezed matter bispectrum and collapsed matter trispectrum in the presence of local PNG, as well as in the presence of a more general “Cosmological Collider” signal sourced by inflationary massive particle exchange. Using N-body simulations with modified initial conditions, I will demonstrate that these models yield unbiased constraints on the amplitude of PNG deep into the non-linear regime (k~2 h/Mpc at z=0). Finally, I will discuss how these non-perturbative methods can provide insight into the scale-dependent bias signature associated with the Cosmological Collider scenario.