Effects of the matter Lagrangian degeneracy in $f(Q,T)$ gravity

Autor: Nájera, José Antonio, Alvarado, Carlos Aráoz
Rok vydání: 2022
Předmět:
Zdroj: Physics of the Dark Universe Volume 38, December 2022, 101141
Druh dokumentu: Working Paper
DOI: 10.1016/j.dark.2022.101141
Popis: In this paper, we investigated the theoretical and cosmological effects of the matter Lagrangian degeneracy in an extension of the Symmetric Teleparallel Equivalent of General Relativity, denoted as $f (Q, T )$ gravity. This degeneracy comes from the fact that both $\mathcal{L}_m = p$ and $\mathcal{L}_m = -\rho$ can give rise to the stress-energy tensor of a perfect fluid. The $f(Q,T)$ equations depend on the form of the matter Lagrangian and hence they also have a degeneracy that has influence on the density evolution of dust matter and radiation, on the form of the generalized Friedmann equations and also shows changes in the cosmological parameters confidence regions when performing Monte Carlo Markov Chains analyses. Our results suggest that since changing the matter Lagrangian causes different theoretical and cosmological results, future studies in $f(Q,T)$ gravity should consider both forms of the matter Lagrangians to account for the different mathematical and observational results.
Comment: Accepted for publication in Physics of the Dark Universe
Databáze: arXiv