PIRSA:18010075

Video URL

https://pirsa.org/18010075

Axion strings and domain walls

Hardy, E. (2018). Axion strings and domain walls. Perimeter Institute for Theoretical Physics. https://pirsa.org/18010075

Hardy, Edward. Axion strings and domain walls. Perimeter Institute for Theoretical Physics, Jan. 16, 2018, https://pirsa.org/18010075 

          @misc{ scivideos_PIRSA:18010075,
            doi = {10.48660/18010075},
            url = {https://pirsa.org/18010075},
            author = {Hardy, Edward},
            keywords = {Particle Physics},
            language = {en},
            title = {Axion strings and domain walls},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2018},
            month = {jan},
            note = {PIRSA:18010075 see, \url{https://scivideos.org/pirsa/18010075}}
          }

Edward Hardy University of Liverpool

Talk numberPIRSA:18010075
DOI10.48660/18010075
Source RepositoryPIRSA
Collection
Talk Type Scientific Series
Subject

Abstract

I will discuss the calculation of the axion dark matter relic abundance produced by strings and domain walls in the early universe. These objects appear if the global symmetry that the axion is associated with is unbroken at the end of inflation, and in this scenario there is, in principle, a unique prediction for the axion dark matter mass. I will present results from numerical simulations that indicate that the density of strings may be significantly larger than previously thought, leading to a corresponding change in the required axion dark matter mass. I will also discuss the difficulties in computing the energy spectrum of axions produced in the physically relevant regime, and the remaining uncertainties and challenges.