Torsion-Induced Modification to Friedmann Equations in $AdSL_{4}$ Gauged Gravity

TL;DR

This paper explores how torsion in an $AdSL_{4}$-gauged gravity framework modifies Friedmann equations, leading to de Sitter-like cosmic acceleration driven by gauge fields without exotic matter.

Contribution

It introduces a gauge-theoretic extension of gravity with torsion that naturally produces cosmological acceleration and effective cosmological constants from gauge fields.

Findings

Torsion modifies Einstein-Cartan equations in $AdSL_{4}$ gravity.

Derived Friedmann equations include torsional contributions.

Cosmic acceleration can arise from gauge fields without exotic matter.

Abstract

We study the solution of the gravitational field equations in $AdSL_{4}$-gauged gravity, a gauge-theoretic extension of general relativity based on the $AdSL_{4}$ algebra. In this formulation, the antisymmetric gauge field $B^{ab}$, associated with additional $AdSL_{4}$ tensorial generators, induces space-time torsion via the relation $K^{ab}=\mu B^{ab}$, where $K^{ab}$ denotes the contorsion 1-form. The presence of torsion modifies both the spin connection and curvature, leading to an extended set of Einstein-Cartan field equations. Focusing on spatially homogeneous and isotropic cosmological backgrounds, we derive the modified Friedmann equations which explicitly incorporate the torsional contribution. The resulting acceleration equation admits de Sitter-like solutions in which cosmic acceleration originates purely from the gauge-theoretic structure of enlarged four-dimensional space-time symmetries. Within this formulation, the dynamical components of the gauge field $B^{ab}$ emerge naturally as a source of the effective cosmological constants, without the introduction of exotic matter sources. Furthermore, our analysis shows that the torsion-driven cosmological phase in $AdSL_{4}$-gauged gravity can reproduce an effective equation-of-state parameter $\omega_{B}=-1/3$, establishing a connection between space-time torsion and cosmic-string-like dynamics.