Relativistic effects in large-scale structure

The London Relativity and Cosmology Seminar
Camille Bonvin (Cambridge)
March 19th, 2014 at 16:30
Maths 103

In the past few years it has been shown that the two-point correlation function of galaxies is affected by relativistic effects at large scales. Various terms like gravitational redshift, Doppler effects or time delay corrections induce subtle changes in the correlation function. These effects are however subdominant on all but the largest scales, rendering their detection challenging. In this talk, I wil present a novel method to measure relativistic effects in large-scale structure by looking at the anti-symmetric part of the correlation function between two populations of galaxies. I will show that gravitational redshift and Doppler terms induce a dipole modulation in the correlation function, which allows to isolate the relativistic effects at scales accessible by current surveys.