High Energy Physics Seminar

Theories that seek to explain the outstanding puzzles of the Standard Model of particle physics often predict new, light, feebly-interacting particles. In this talk, I will focus on the early universe, where even a small trace of hyperlight scalar fields can be observed through the power of the cosmic microwave background. Scalar fields which interact with photons and electrons provide concrete microphysical models of varying-constant scenarios, invoked as a potential resolution of discrepant measurements of the universe's expansion rate. I will discuss cosmological and laboratory constraints on these models, including measurements of quasar absorption lines, abundances of light elements, and universality of free fall. I will focus on hyperlight scalar fields which make up part of the dark matter today,  their dynamics and signatures in the early universe, and their effect on the cosmic microwave background and inferred cosmological parameters.    

The talk is in 469 Lauritsen.

Contact theoryinfo@caltech.edu for Zoom link.