Metric-Affine F(T,Q) gravity: cosmological implications and constraints

Abstract

Abstract In this paper, we investigate some exact cosmological models in Metric-Affine F(T, Q) gravity, with observational constraints. The Metric-Affine F(T, Q) gravity is some kind of unification of two known gravity theories, namely, the F(T) gravity and the F(Q) gravity. We obtain the field equations of the Metric-Affine theory by considering the metric tensor and the general affine connection as independent variables. We then focus on the particular case in which the F(T, Q) function characterizing the aforementioned metric-affine models is linear, that is, F(T, Q) = λ T + μ Q. We investigate this linear case and consider a Friedmann-Lemaître-Robertson-Walker background to study cosmological aspects and applications. We have obtained three exact solutions of the modified field equations in two different cases, T and Q, using the Hubble function H(t) and the scale factor a(t). We then placed observational constraints on these solutions using the Hubble H(z) datasets and the MCMC analysis. We have investigated the deceleration parameter q(z) and effective EoS parameters, and a comparative study of all three models with ΛCDM model has been carried out.