Can the gravitational wave background feel wiggles in spacetime?

Fuente: arXiv
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Autori principali: Ye, Gen, Silvestri, Alessandra
Natura: Preprint
Pubblicazione: 2023
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author Ye, Gen
Silvestri, Alessandra
author_facet Ye, Gen
Silvestri, Alessandra
contents Recently the international pulsar timing array collaboration has announced the first strong evidence for an isotropic gravitational wave background (GWB). We propose that rapid small oscillations (wiggles) in the Hubble parameter would trigger a resonance with the propagating gravitational waves, leaving novel signature in the GWB spectrum in the form of sharp resonance peaks. The proposed signal can appear at all frequency ranges and is common to continuous spectrum GWBs with arbitrary origin. Due to its resonant nature, the signal strength differs by a perturbation order depending on whether the GWB is primordial or not, which makes it a smoking gun for the primordial origin of the observed GWB. We show that a large part of the parameter space of such signal can be constrained by near future PTA observations, while fitting the signal template to the current NanoGrav 15yr data already hints an interesting feature near 15 nHz.
format Preprint
id arxiv_https___arxiv_org_abs_2307_05455
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Can the gravitational wave background feel wiggles in spacetime?
Ye, Gen
Silvestri, Alessandra
Cosmology and Nongalactic Astrophysics
General Relativity and Quantum Cosmology
High Energy Physics - Theory
Recently the international pulsar timing array collaboration has announced the first strong evidence for an isotropic gravitational wave background (GWB). We propose that rapid small oscillations (wiggles) in the Hubble parameter would trigger a resonance with the propagating gravitational waves, leaving novel signature in the GWB spectrum in the form of sharp resonance peaks. The proposed signal can appear at all frequency ranges and is common to continuous spectrum GWBs with arbitrary origin. Due to its resonant nature, the signal strength differs by a perturbation order depending on whether the GWB is primordial or not, which makes it a smoking gun for the primordial origin of the observed GWB. We show that a large part of the parameter space of such signal can be constrained by near future PTA observations, while fitting the signal template to the current NanoGrav 15yr data already hints an interesting feature near 15 nHz.
title Can the gravitational wave background feel wiggles in spacetime?
topic Cosmology and Nongalactic Astrophysics
General Relativity and Quantum Cosmology
High Energy Physics - Theory
url https://arxiv.org/abs/2307.05455