A designer approach to f(Q) gravity and cosmological implications
Abstract
We investigate the evolution of linear perturbations in the Symmetric Teleparallel Gravity, namely f(Q) gravity, for which we design the f(Q) function to match specific expansion histories. We consider different evolutions of the effective dark energy equation of state, w_{Q}(a) , which includes w_{Q} =  1 , a constant w_{Q} ≠  1 and a fast varying equation of state. We identify clear patterns in the effective gravitational coupling, which accordingly modifies the linear growth of large scale structures. We provide theoretical predictions for the product of the growth rate f ̃ and the root mean square of matter fluctuations σ_{8}, namely f ̃ σ_{8} and for the sign of the crosscorrelation power spectrum of the galaxy fluctuations and the cosmic microwave background radiation anisotropies. These properties can be used to distinguish the f(Q) gravity from the standard cosmological model using accurate cosmological observations.
 Publication:

Physics of the Dark Universe
 Pub Date:
 March 2022
 DOI:
 10.1016/j.dark.2022.100980
 arXiv:
 arXiv:2202.04637
 Bibcode:
 2022PDU....3500980A
 Keywords:

 Cosmology;
 Modified gravity;
 Growth of structures;
 Astrophysics  Cosmology and Nongalactic Astrophysics;
 General Relativity and Quantum Cosmology
 EPrint:
 14 pages, 12 figures, Accepted for publication in Physics of the Dark Universe