# Defying the laws of Gravity I: model-independent reconstruction of the Universe expansion from growth data

## TL;DR

This paper employs model-independent methods to reconstruct the Universe's expansion history from growth data, confirming consistency with the standard cosmological model and General Relativity.

## Contribution

It introduces two novel, model-independent techniques—crossing statistics and Gaussian processes—for reconstructing cosmic growth and expansion histories from observational data.

## Key findings

- Results align with the flat-$\Lambda$CDM model
- Constraints on matter density and fluctuation amplitude are consistent with current cosmology
- Current data supports General Relativity as the gravity theory

## Abstract

Using redshift space distortion data, we perform model-independent reconstructions of the growth history of matter inhomogeneity in the expanding Universe using two methods: crossing statistics and Gaussian processes. We then reconstruct the corresponding history of the Universe background expansion and fit it to type Ia supernovae data, putting constraints on $(\Omega_\mathrm{m,0},\sigma_{8,0})$. The results obtained are consistent with the concordance flat-$\Lambda$CDM model and General Relativity as the gravity theory given the current quality of the inhomogeneity growth data.