Confronting General Relativity with Further Cosmological Data

TL;DR

This paper investigates potential deviations from general relativity across different redshifts and scales using cosmological data, finding significant deviations at low redshift in some datasets, and discusses future survey prospects.

Contribution

It extends previous analyses by incorporating additional cosmological probes and examining correlations between deviations, providing a more comprehensive model-independent test of gravity.

Findings

Low redshift deviations from GR at 99% confidence in some data sets.

Discrepancies traced to specific weak lensing data properties.

Future surveys like BigBOSS can significantly tighten constraints.

Abstract

Deviations from general relativity in order to explain cosmic acceleration generically have both time and scale dependent signatures in cosmological data. We extend our previous work by investigating model independent gravitational deviations in bins of redshift and length scale, by incorporating further cosmological probes such as temperature-galaxy and galaxy-galaxy cross-correlations, and by examining correlations between deviations. Markov Chain Monte Carlo likelihood analysis of the model independent parameters fitting current data indicates that at low redshift general relativity deviates from the best fit at the 99% confidence level. We trace this to two different properties of the CFHTLS weak lensing data set and demonstrate that COSMOS weak lensing data does not show such deviation. Upcoming galaxy survey data will greatly improve the ability to test time and scale dependent extensions to gravity and we calculate the constraints that the BigBOSS galaxy redshift survey could enable.