Particle Physics Seminar: The post-inflationary axion

Abstract:

The axion is a hypothetical particle that solves the strong CP problem of quantum chromodynamics (QCD) while simultaneously being an excellent dark matter candidate. If the axion is generated after inflation, many unique objects arise from the theory, from axion strings and domain walls to oscillons, miniclusters, and axion stars. The result is many potentially observable signatures, whether in the CMB, the gravitational wave background or in neutron star data. More importantly, this scenario is entirely deterministic, allowing precise predictions through numerical simulations. In this talk, I will go through the cosmological history of such a post-inflationary axion to put the various phenomena into context and highlight the remaining open questions.

Seminar Organizers: Dr. Michael Geller & Dr. Adi Ashkanzi