Galaxy clusters, cosmic chronometers and the Einstein equivalence principle
Abstract
The Einstein equivalence principle in the electromagnetic sector can be violated in modifications of gravity theory generated by a multiplicative coupling of a scalar field to the electromagnetic Lagrangian. In such theories, deviations of the standard result for the cosmic distance duality relation, and a variation of the fine structure constant are expected and are unequivocally intertwined. In this paper, we search for these possible cosmological signatures by using galaxy cluster gas mass fraction measurements and cosmic chronometers. No significant departure from general relativity is found regardless of our assumptions about cosmic curvature or a possible depletion factor evolution in cluster measurements.
 Publication:

Journal of Cosmology and Astroparticle Physics
 Pub Date:
 October 2021
 DOI:
 10.1088/14757516/2021/10/084
 arXiv:
 arXiv:2107.14169
 Bibcode:
 2021JCAP...10..084M
 Keywords:

 cosmology of theories beyond the SM;
 galaxy clusters;
 modified gravity;
 Astrophysics  Cosmology and Nongalactic Astrophysics;
 General Relativity and Quantum Cosmology
 EPrint:
 11 pages, 4 figures, I table, Accepted Version for Publication in JCAP