COFFE: a code for the full-sky relativistic galaxy correlation function

TL;DR

COFFE is a publicly available code that accurately computes the full-sky galaxy two-point correlation function, including relativistic effects, and forecasts the detectability of lensing signals in upcoming surveys.

Contribution

The paper introduces COFFE, a new code that calculates the full-sky galaxy correlation function with relativistic corrections and provides covariance estimates for key estimators.

Findings

Lensing signal in the correlation function is detectable with high significance in future surveys.

COFFE accurately models relativistic and wide angle effects in the galaxy correlation function.

Forecasts show lensing can be detected with a signal-to-noise ratio greater than 10.

Abstract

We present a public version of the code COFFE (COrrelation Function Full-sky Estimator) available at https://github.com/JCGoran/coffe. The code computes the galaxy two-point correlation function and its multipoles in linear perturbation theory, including all relativistic and wide angle corrections. COFFE also calculates the covariance matrix for two physically relevant estimators of the correlation function multipoles. We illustrate the usefulness of our code by a simple but relevant example: a forecast of the detectability of the lensing signal in the multipoles of the two-point function. In particular, we show that lensing should be detectable in the multipoles of the two-point function, with a signal-to-noise larger than 10, in future surveys like Euclid or the SKA.