Gravitational-wave background in bouncing models from semi-classical, quantum and string gravity

Ido Ben-Dayan, Gianluca Calcagni, Maurizio Gasperini, Anupam Mazumdar, Eliseo Pavone, Udaykrishna Thattarampilly, Amresh Verma

Research output: Contribution to journalArticlepeer-review

Abstract

We study the primordial spectra and the gravitational-wave background (GWB) of three models of semi-classical, quantum or string gravity where the big bang is replaced by a bounce and the primordial tensor spectrum is blue: ekpyrotic universe with fast-rolling Galileons, string-gas cosmology with Atick-Witten conjecture and pre-big-bang cosmology. We find that the ekpyrotic scenario with Galileons does not produce a GWB amplitude detectable by present or third-generation interferometers, while the Atick-Witten-based string-gas model is ruled out in its present form for violating the big-bang-nucleosynthesis bound, contrary to the original string-gas scenario. In contrast, the GWB of the pre-big-bang scenario falls within the sensitivity window of both LISA and Einstein Telescope, where it takes the form of a single or a broken power law depending on the choice of parameters. The latter will be tightly constrained by both detectors.

Original languageEnglish
Article number058
JournalJournal of Cosmology and Astroparticle Physics
Volume2024
Issue number9
DOIs
StatePublished - 1 Sep 2024

Keywords

  • Gravitational waves in GR and beyond: theory
  • primordial gravitational waves (theory)
  • quantum gravity phenomenology
  • string theory and cosmology

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics

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