Cosmological evolution and dark energy in osculating Barthel-Randers geometry

TL;DR

This paper explores a novel Finslerian cosmological model based on osculating Barthel-Randers geometry, deriving modified Friedmann equations, analyzing dark energy effects, and fitting models to observational data.

Contribution

It introduces a new cosmological framework using Barthel-Randers geometry, deriving generalized equations, and demonstrating compatibility with observations.

Findings

The model admits de Sitter solutions.

An effective cosmological constant can be generated.

Models fit observational Hubble data satisfactorily.

Abstract

We consider the cosmological evolution in an osculating point Barthel-Randers type geometry, in which to each point of the space-time manifold an arbitrary point vector field is associated. This Finsler type geometry is assumed to describe the physical properties of the gravitational field, as well as the cosmological dynamics. For the Barthel-Randers geometry the connection is given by the Levi-Civita connection of the associated Riemann metric. The generalized Friedmann equations in the Barthel-Randers geometry are obtained by considering that the background Riemannian metric in the Randers line element is of Friedmann-Lemaitre-Robertson-Walker type. The matter energy balance equation is derived, and it is interpreted from the point of view of the thermodynamics of irreversible processes in the presence of particle creation. The cosmological properties of the model are investigated in detail, and it is shown that the model admits a de Sitter type solution, and that an effective cosmological constant can also be generated. Several exact cosmological solutions are also obtained. A comparison of three specific models with the observational data and with the standard $\Lambda$CDM model is also performed by fitting the observed values of the Hubble parameter, with the models giving a satisfactory description of the observations.