Speaker: Junwu Huang
Title: Abstract:Cosmic axion strings II: A cosmological plasma collider
Zoom: https://zoom.us/j/186024391
Host: Markus Luty
Abstract : We continue our discussion of early and late time signatures of axion strings by considering the effects of electromagnetic field on the axion string. Axion strings passing through galaxies obtain a huge charge and current density, which is neutralized by a dense plasma of bound state Standard Model particles forming a one dimensional "atom". The charged wave packets on the string, as well as the dense plasma outside, travel at nearly the speed of light along the string. The collisions of these packets of plasma can have luminosities up to seven orders of magnitude larger than the solar luminosity, and last for thousands of years, making them visible at radio telescopes even when they occur cosmologically far away. The new observables are complementary to the CMB observables discussed last week, and are sensitive to a similar motivated parameter range, allowing for non-trivial cross correlations.
