Gravitational waves induced by scalar-tensor mixing
Abstract
This paper explores the physics of second-order gravitational waves (GWs) induced by scalar-tensor perturbation interactions in the radiation-dominated Universe. We investigate the distinctive signatures of these GWs and their detectability compared to scalar-induced GWs. Unlike scalar-scalar induced GWs, scalar-tensor induced GWs do not present resonances or a logarithmic running in the low frequency tail in the case of peaked primordial spectra. But, interestingly, they partly inherit any primordial parity violation of tensor modes. We find that chirality in primordial GWs can lead to distinguishing effects in scalar-tensor induced GWs in the ultraviolet (UV) region. We also address a potential divergence in our GWs and explore possible solutions. This study contributes to our understanding of GWs in the early Universe and their implications for cosmology and GWs detection.
Cite
@article{arxiv.2307.05404,
title = {Gravitational waves induced by scalar-tensor mixing},
author = {Pritha Bari and Nicola Bartolo and Guillem Domènech and Sabino Matarrese},
journal= {arXiv preprint arXiv:2307.05404},
year = {2024}
}
Comments
35 pages, 7 figures, Published in Physical Review D