Stochastic gravitational-wave background in quantum gravity
Abstract
Among all cosmological quantum-gravity or quantum-gravity-inspired scenarios, only very few predict a blue-tilted primordial tensor spectrum. We explore five of them and check whether they can generate a stochastic gravitational-wave background detectable by present and future interferometers: non-local quantum gravity, string-gas cosmology, new ekpyrotic scenario, Brandenberger-Ho non-commutative inflation and multi-fractional spacetimes. We show that non-local quantum gravity is unobservable, while all the other models can reach the strain sensitivity of DECIGO but not that of LIGO-Virgo-KAGRA, LISA or Einstein Telescope. Other quantum-gravity models with red-tilted spectra (most loop quantum cosmologies) or with exceptionally tiny quantum corrections (Wheeler-DeWitt quantum cosmology) are found to be non-detectable.
Cite
@article{arxiv.2012.00170,
title = {Stochastic gravitational-wave background in quantum gravity},
author = {Gianluca Calcagni and Sachiko Kuroyanagi},
journal= {arXiv preprint arXiv:2012.00170},
year = {2021}
}
Comments
1+41 pages, 12 figures, 1 table. v2: minor typos corrected, clarifications added