Constraining General Modifications of Gravity during Reionisation

TL;DR

This paper explores how intensity mapping of 21cm line fluctuations during reionisation can constrain modifications to gravity, focusing on parameters like initial conditions and scale-dependent deviations from General Relativity.

Contribution

It introduces a framework for testing modified gravity during reionisation using intensity mapping power spectra, including simulations and forecast analyses for upcoming surveys.

Findings

Intensity mapping can constrain gravity modifications during reionisation.

Simulations show sensitivity of power spectra to gravity parameters.

Forecasts indicate potential for SKA to test gravity deviations.

Abstract

Intensity mapping enables us to test cosmology and fundamental physics during the Epoch of Reionisation, with power spectra of line fluctuations probing a large range of scales and redshifts. Cosmological volumes of 21cm line fluctuations in general modified gravity scenarios are presented, where additional parameters are the initial condition parameter $\alpha$ of matter perturbations and the scale-dependent modified gravity parameter $Y$ that measures deviations from General Relativity in the Poisson equation. For upcoming surveys like the SKA we forecast, using the power spectra derived from our simulations, the ability of intensity mapping to constrain modifications of gravity during reionisation, as well as investigate correlations with astrophysical parameters.