Testing modified gravity models with recent cosmological observations

TL;DR

This study tests five modified gravity models against recent cosmological data, finding that the standard Lambda Cold Dark Matter model remains most favored and that current growth data cannot distinguish MG models from it.

Contribution

It provides a comprehensive observational comparison of multiple MG models with current data, highlighting their limitations and the dominance of Lambda CDM.

Findings

MG models do not significantly improve fit over Lambda CDM

Lambda CDM remains the most preferred model according to AIC and BIC

Current growth factor data are insufficient to differentiate MG models from Lambda CDM

Abstract

We explore the cosmological implications of five modified gravity (MG) models by using the recent cosmological observational data, including the recently released SNLS3 type Ia supernovae sample, the cosmic microwave background anisotropy data from the Wilkinson Microwave Anisotropy Probe 7-yr observations, the baryon acoustic oscillation results from the Sloan Digital Sky Survey data release 7, and the latest Hubble constant measurement utilizing the Wide Field Camera 3 on the Hubble Space Telescope. The MG models considered include the Dvali-Gabadadze-Porrati(DGP) model, two $f(R)$ models, and two $f(T)$ models. We find that compared with the $\Lambda$CDM model, MG models can not lead to a appreciable reduction of the $\chi^2_{min}$. The analysis of AIC and BIC shows that the simplest cosmological constant model($\Lambda$CDM) is still most preferred by the current data, and the DGP model is strongly disfavored. In addition, from the observational constraints, we also reconstruct the evolutions of the growth factor in these models. We find that the current available growth factor data are not enough to distinguish these MG models from the $\Lambda$CDM model.