Preprint: https://arxiv.org/abs/2405.10937 Title: Gravitational waves from low-scale cosmic strings Authors: - Kai Schmitz (1) [https://inspirehep.net/authors/1071227] - Tobias Schröder (1) [https://inspirehep.net/authors/2174896] Affiliations: (1) University of Münster, Institute for Theoretical Physics, Münster, Germany 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 ≲ 10^9 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 f_cut 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 f_cut. 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 ∼ 10^9 GeV, the novel features in the GW spectrum are within the sensitivity reach of future experiments such as BBO and DECIGO.

Preprint:https://arxiv.org/abs/2404.13035Title:Embedded domain walls and electroweak baryogenesisAuthors:- Robert Brandenberger (1) [https://inspirehep.net/a...

Pulsar Timing Array (PTA) collaborations around the globe recently announced compelling evidence for a gravitational-wave background (GWB) at nanohertz frequencies. This breakthrough achievement has i...

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