Cosmic Acceleration with Torsion and Non-metricity in Friedmann-like Universes

TL;DR

This paper derives a generalized cosmic acceleration equation incorporating torsion and non-metricity in FLRW universes, exploring their effects on the universe's expansion rate.

Contribution

It presents the most general form of the acceleration equation with torsion and non-metricity in FLRW spacetimes, extending standard cosmological models.

Findings

Conditions for torsion and non-metricity to accelerate expansion

Conditions for torsion and non-metricity to decelerate expansion

Generalized acceleration equation including non-Riemannian degrees of freedom

Abstract

Starting from the generalized Raychaudhuri equation with torsion and non-metricity, and considering an FLRW spacetime we derive the most general form of acceleration equation in the presence of torsion and non-metricity. That is we derive the cosmic acceleration equation when the nonRiemannian degrees of freedom are also taken into account. We then discuss some conditions under which torsion and non-metricity accelerate/decelerate the expansion rate of the Universe.