Cosmic acceleration: Inhomogeneity versus vacuum energy

TL;DR

This paper proposes that the observed cosmic acceleration can be explained by inhomogeneities in the universe's matter distribution rather than by dark energy or vacuum energy, challenging the standard cosmological model.

Contribution

It introduces a Local Rotational Symmetric inhomogeneous spacetime model that accounts for cosmic acceleration through matter inhomogeneity, relaxing the Cosmological Principle.

Findings

Inhomogeneity can mimic cosmic acceleration observed in supernova data.

The model maintains local isotropy consistent with CBR experiments.

It offers an alternative to dark energy explanations for acceleration.

Abstract

In this essay, I present an alternative explanation for the cosmic acceleration which appears as a consequence of recent high redshift Supernova data. In the usual interpretation, this cosmic acceleration is explained by the presence of a positive cosmological constant or vacuum energy, in the background of Friedmann models. Instead, I will consider a Local Rotational Symmetric (LRS) inhomogeneous spacetime, with a barotropic equation of state for the cosmic matter. Within this framework the kinematical acceleration of the cosmic fluid or, equivalently, the inhomogeneity of matter, is just the responsible of the SNe Ia measured cosmic acceleration. Although in our model the Cosmological Principle is relaxed, it maintains local isotropy about our worldline in agreement with the CBR experiments.