Alleviating $H_0$ tension in scalar-tensor and bi-scalar-tensor theories
Abstract
We investigate scalar-tensor and bi-scalar-tensor modified theories of gravity that can alleviate the tension. In the first class of theories we show that choosing particular models with shift-symmetric friction term we are able to alleviate the tension by obtaining smaller effective Newton's constant at intermediate times, a feature that cannot be easily obtained in modified gravity. In the second class of theories, which involve two extra propagating degrees of freedom, we show that the tension can be alleviated, and the mechanism behind it is the phantom behavior of the effective dark-energy equation-of-state parameter. Hence, scalar-tensor and bi-scalar-tensor theories have the capability of alleviating tension with both known sufficient late-time mechanisms.
Keywords
Cite
@article{arxiv.2308.16044,
title = {Alleviating $H_0$ tension in scalar-tensor and bi-scalar-tensor theories},
author = {Maria Petronikolou and Emmanuel N. Saridakis},
journal= {arXiv preprint arXiv:2308.16044},
year = {2023}
}
Comments
20 pages, 4 figures, Invited Contribution to Universe Special Issue "Modified Gravity Approaches to the Tensions of LambdaCDM", with Editors Eleonora Di Valentino, Leandros Perivolaropoulos, Jackson Levi Said