Beyond the plane-parallel and Newtonian approach: Wide-angle redshift distortions and convergence in general relativity

TL;DR

This paper extends the analysis of galaxy redshift space correlations by including all general relativistic effects, revealing significant corrections on large scales that are crucial for future cosmological surveys.

Contribution

It introduces a comprehensive relativistic framework for wide-angle galaxy correlations, surpassing the Newtonian approximation on large cosmological scales.

Findings

Relativistic corrections can reach nearly 10% on Gpc scales.

New terms in correlations become significant at high redshifts.

Future surveys like SKA and Euclid need to account for these effects.

Abstract

We extend previous analyses of wide-angle correlations in the galaxy power spectrum in redshift space to include all general relativistic effects. These general relativistic corrections to the standard approach become important on large scales and at high redshifts, and they lead to new terms in the wide-angle correlations. We show that in principle the new terms can produce corrections of nearly 10 % on Gpc scales over the usual Newtonian approximation. General relativistic corrections will be important for future large-volume surveys such as SKA and Euclid, although the problem of cosmic variance will present a challenge in observing this.