Stability Properties of Self-Similar Solutions in Symmetric Teleparallel f(Q)-Cosmology

Abstract

Self-similar cosmological solutions correspond to spacetimes that admit a homothetic symmetry. The physical properties of self-similar solutions can describe important eras of the cosmological evolution. Recently, self-similar cosmological solutions were derived for symmetric teleparallel fQ-theory with different types of connections. In this work, we study the stability properties of the self-similar cosmological solutions in order to investigate the effects of the different connections on the stability properties of the cosmic history. For the background geometry, we consider the isotropic Friedmann–Lemaître–Robertson–Walker space and the anisotropic and homogeneous Bianchi I space, for which we investigate the stability properties of Kasner-like universes.

The Brans–Dicke field in non-metricity gravity: cosmological solutions and conformal transformations

“…At this juncture, it is crucial to highlight that, for ω = 0, the latter gravitational theory is equivalent to the non-metricity theory with boundary term, specifically with the f (Q, B) = Q + f (B) theory of gravity [41].…”

“…The first scalar field corresponds to the degrees of freedom associated with the higher-order derivatives of the theory, whereas the second scalar field is linked to the connection defined in the non-coincidence gauge. For further investigations into f (Q)-gravity and its generalizations, we recommend referring to the works cited in [32][33][34][35][36][37][38][39][40][41][42][43] and the references provided therein.…”