Propagating speed of primordial gravitational waves and inflation
Cosmology and Nongalactic Astrophysics
2016-08-10 v3 General Relativity and Quantum Cosmology
High Energy Physics - Theory
Abstract
We show that if the propagating speed of gravitational waves (GWs) gradually diminishes during inflation, the power spectrum of primordial GWs will be strongly blue, while that of the primordial scalar perturbation may be unaffected. We also illustrate that such a scenario is actually a disformal dual to the superinflation, but it does not have the ghost instability. The blue tilt obtained is , which may significantly boost the stochastic GWs background at the frequency band of Advanced LIGO/Virgo, as well as the space-based detectors.
Keywords
Cite
@article{arxiv.1602.05431,
title = {Propagating speed of primordial gravitational waves and inflation},
author = {Yong Cai and Yu-Tong Wang and Yun-Song Piao},
journal= {arXiv preprint arXiv:1602.05431},
year = {2016}
}
Comments
18 pages, 4 figures; published version in PRD; two appendixes were moved to the main body; references and comments added, presentation improved