Speaker
Description
We study new signatures associated with electromagnetic properties of axion strings. We focus
on charge deposition onto axion strings from electromagnetic fields and
the subsequent novel neutralizing
mechanisms due to bound state formation. While early universe
signatures appear unlikely, there are a plethora of late time
signatures. Axion strings passing through galaxies obtain an enormous
charge density, which is quickly 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. These
packets of high energy plasma collide with a center of mass energy of
up to $10^{9}$ GeV. These collisions 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 at cosmological distances.
