21st Patras Workshop on Axions, WIMPs and WISPs

On Gravitational Radiation from Cosmic String Segments

Not scheduled

20m

University of Western Australia

Poster Presentation

Speaker

Masahiro Ibe (Institute for Cosmic Ray Research, University of Tokyo)

Description

Cosmic strings are predicted in many extensions of the Standard Model. Depending on the symmetry-breaking pattern, they can be either stable or metastable. Metastable strings have recently attracted attention as a possible source of the stochastic gravitational-wave background reported by pulsar timing array experiments.
When metastable strings decay, they fragment into segments ending on monopoles and antimonopoles. These oscillating segments have been proposed as an additional source of gravitational waves. In this talk, I will show that thermal fluctuations on the strings exert an effective drag on the endpoint monopoles, strongly damping the oscillations. As a result, the gravitational-wave emission from string segments is negligible in realistic cosmological settings.