Large Scale Structure Constraints for a Class of f(R) Theories of Gravity

TL;DR

This paper evaluates f(R) gravity theories by comparing their predicted matter power spectra with SDSS data, highlighting conflicts with observations and emphasizing the importance of accurate perturbation analysis.

Contribution

It provides a detailed analysis of matter power spectra in f(R) theories without relying on the quasi-static approximation, using a dynamical systems approach and confronting results with observational data.

Findings

f(R) models show significant conflict with SDSS data

Proper background evolution and initial conditions are crucial for accurate predictions

Theoretical power spectra do not align well with observations

Abstract

Over the last few years much attention has been given to the study of modified gravity theories in order to find a more natural explanation for the late time acceleration of the Universe. Nevertheless, a comparison of the matter power spectrum predictions made by these theories with available data has not yet been subjected to a detailed analysis. In the context of f(R) theories of gravity we study the predicted power spectra using both a dynamical systems approach for the background and solving for the matter perturbations without using the quasi-static approximation, comparing the theoretical results with several SDSS data. The importance of studying the first order perturbed equations by assuming the correct background evolution and the relevance of the initial conditions are also stressed. We determine the statistical significance in relation to the observational data and demonstrate their conflict with existing observations.