Gravitational waves from low-scale cosmic strings

Schmitz, Kai; Schröder, Tobias

Research article (journal) | Peer reviewed

Abstract

Cosmic strings are a common prediction in many grand unified theories and a promising source of stochastic gravitational waves (GWs) from the early Universe. In this paper, we point out that the GW signal from cosmic strings produced at a comparatively low energy scale, v≲109  GeV, exhibits several novel features that are not present in the case of high-scale cosmic strings. Our findings notably include (i) a sharp cutoff frequency fcut in the GW spectrum from the fundamental oscillation mode on closed string loops and (ii) an oscillating pattern in the total GW spectrum from all oscillation modes whose local minima are located at integer multiples of fcut. These features reflect the fact that string loops produced in the early Universe fail to shrink to zero size because of GW emission within the age of the Universe, if their tension is low enough. In addition, they offer an exciting opportunity to directly probe the discrete spectrum of oscillation modes on closed string loops in GW observations. For strings produced at a scale v∼109  GeV, the novel features in the GW spectrum are within the sensitivity reach of future experiments such as BBO and DECIGO.

Details about the publication

JournalPhysical Review D (PRD) (Phys Rev D)
Volume110
Issue6
Article number063549
StatusPublished
Release year2024 (23/09/2024)
Language in which the publication is writtenEnglish
DOI10.1103/PhysRevD.110.063549
KeywordsGravitational waves; particle cosmology; cosmic strings

Authors from the University of Münster

Schmitz, Kai
Junior professorship for theoretical elementary particle physics (Prof. Schmitz)
Schröder, Tobias
Junior professorship for theoretical elementary particle physics (Prof. Schmitz)