Bouncing Cosmology in VCDM
General Relativity and Quantum Cosmology
2023-04-28 v2 Cosmology and Nongalactic Astrophysics
High Energy Physics - Theory
Abstract
We construct an asymmetric bouncing scenario within the VCDM model - also known as type-II minimally modified gravity -, a modified gravity theory with two local physical degrees of freedom. The scenario is exempt of any ghost or gradient instability, ad-hoc matching conditions or anisotropic stress issue (BKL instability). It moreover succeeds in generating the cosmological perturbations compatible with the observations. The scalar spectral index can be adapted by the choice of the equation of state of the matter sector and the form of the VCDM potential leading to an almost scale-invariant power spectrum. Satisfying the CMB bounds on the tensor-to-scalar ratio leads to a blue tensor spectrum.
Cite
@article{arxiv.2212.13561,
title = {Bouncing Cosmology in VCDM},
author = {Alexander Ganz and Paul Martens and Shinji Mukohyama and Ryo Namba},
journal= {arXiv preprint arXiv:2212.13561},
year = {2023}
}
Comments
15 pages, 8 figures; accepted version