Cosmological Boundary Flux Parameter

TL;DR

This paper introduces the Cosmological Boundary Flux Parameter, a geometric approach to explain the cosmological constant, and tests it against observational data, finding a slightly lower Hubble constant than the standard model.

Contribution

It proposes a new geometric boundary flux parameter model for the cosmological constant and performs observational constraints using late-time data.

Findings

The model yields a Hubble constant of 69.80 km/s/Mpc.

The joint analysis results in a smaller H0 compared to ΛCDM.

The approach offers a potential explanation for cosmic acceleration.

Abstract

The {\it{Cosmological Boundary Flux Parameter}} is a novel proposal that attempts to explain the origin of the cosmological parameter $\Lambda$ purely by geometric nature. Then we implement this new approach to a flat FLRW universe along with a barotropic fluid. We present an ansatz in which $\Lambda$ is straightforwardly coupled to the matter sector; therefore, only one additional parameter was introduced: $\lambda$. Also, through a statistical analysis, using late-time data of observational Hubble and type Ia Supernovae, we computed the joint best-fit value of the free parameters by means of the affine-invariant MCMC. We want to emphasise that the joint analysis produces a smaller $H_{0}^{\rm CBFP}=69.80\rm\,\, Km \,s^{-1}\,Mpc^{-1}$ in contrast to the flat $\Lambda$CDM result $H_{0}^{\Lambda\rm CDM}=70.53\rm\,\, Km \,s^{-1}\,Mpc^{-1}$. The work presented here seeks to contribute to the discussion of the possible explanation for the cosmos' acceleration, together with tackling other important questions in modern cosmology.