Signatures of f (Q ) gravity in cosmology
Abstract
We investigate the impact on cosmological observables of f (Q )gravity, a specific class of modified gravity models in which gravity is described by the nonmetricity scalar, Q . In particular we focus on a specific model which is indistinguishable from the Λ colddarkmatter (Λ CDM ) model at the background level, while showing peculiar and measurable signatures at linear perturbation level. These are attributed to a timedependent Planck mass and are regulated by a single dimensionless parameter, α . In comparison to the Λ CDM model, we find for positive values of α a suppressed matter power spectrum and lensing effect on the cosmic microwave background radiation (CMB) angular power spectrum and an enhanced integratedSachsWolfe tail of CMB temperature anisotropies. The opposite behaviors are present when the α parameter is negative. We also investigate the modified gravitational waves (GWs) propagation and show the prediction of the GWs luminosity distance compared to the standard electromagnetic one. Finally, we infer the accuracy on the free parameter of the model with standard sirens at future GWs detectors.
 Publication:

Physical Review D
 Pub Date:
 February 2021
 DOI:
 10.1103/PhysRevD.103.044021
 arXiv:
 arXiv:2101.09242
 Bibcode:
 2021PhRvD.103d4021F
 Keywords:

 Astrophysics  Cosmology and Nongalactic Astrophysics;
 General Relativity and Quantum Cosmology
 EPrint:
 8 pages, 6 figures, accepted for publication in PRD