Hubble Tension and Gravitational Self-Interaction

TL;DR

This paper investigates whether gravitational self-interaction within General Relativity can resolve the Hubble tension by fitting both low- and high-redshift data without extra parameters.

Contribution

It demonstrates that including gravitational self-interaction effects can simultaneously fit low- and high-redshift cosmological data, potentially resolving the Hubble tension.

Findings

Gravitational self-interaction explains the Hubble tension.

Both low- and high-redshift data are well-fitted.

No additional parameters are needed.

Abstract

One of the most important problems vexing the $\Lambda$CDM cosmological model is the Hubble tension. It arises from the fact that measurements of the present value of the Hubble parameter performed with low-redshift quantities, e.g., the Type IA supernova, tend to yield larger values than measurements from quantities originating at high-redshift, e.g., fits of cosmic microwave background radiation. It is becoming likely that the discrepancy, currently standing at $5\sigma$, is not due to systematic errors in the measurements. Here we explore whether the self-interaction of gravitational fields in General Relativity, which are traditionally neglected when studying the evolution of the universe, can explain the tension. We find that with field self-interaction accounted for, both low- and high-redshift data are simultaneously well-fitted, thereby showing that gravitational self-interaction could explain the Hubble tension. Crucially, this is achieved without introducing additional parameters.