Cosmology with running parameters

TL;DR

This paper proposes that a variable cosmological term, possibly with a changing gravitational constant, can naturally explain the evolving dark energy equation of state suggested by observations, offering an alternative to dynamical dark energy fields.

Contribution

It introduces the idea that a variable cosmological term and gravitational coupling can account for dark energy evolution without invoking dynamical fields.

Findings

A variable cosmological term can mimic evolving dark energy behavior.

Variable gravitational coupling may also play a role in cosmic acceleration.

The approach offers a new perspective on dark energy modeling.

Abstract

The experimental evidence that the equation of state (EOS) of the dark energy (DE) could be evolving with time/redshift (including the possibility that it might behave phantom-like near our time) suggests that there might be dynamical DE fields that could explain this behavior. We propose, instead, that a variable cosmological term (including perhaps a variable Newton's gravitational coupling too) may account in a natural way for all these features.