Towards degeneracy problem breaking by large scale structures methods

TL;DR

This paper reviews how large-scale structure methods can address the degeneracy problem in modified gravity theories by identifying observable quantities that distinguish them from standard cosmology.

Contribution

It proposes using specific observational measurements, like scalar perturbation growth and CMB tensor evolution, to break degeneracies among modified gravity models.

Findings

Growth of scalar perturbations can differentiate theories.

CMB tensor perturbations evolution helps discriminate models.

Observational strategies to test modified gravity theories.

Abstract

An arguable aspect of the modified gravity theories is that many of them present the so-called degeneracy problem. For instance, the cosmological evolution, gravitational collapse and the main features of standard black-hole configurations, can be mimicked by many of those theories. In this communication we revise briefly the appropriate observable quantities to be measured in order to discard alternative theories to LCDM, such as the observed growth of scalar perturbations with Sloan data and the CMB tensor perturbations evolution.