Relativistic effects beyond linear theory

I will discuss the Large Scale Structure power spectrum and bispectrum in a relativistic framework. To first order, a relativistic description includes terms beyond the Kaiser approximation. I will show how they can be isolated by correlating different probes and how to optimise their detection. Moreover, I will explain how some of these effects can bias the parameters which test the deviation from GR. Beyond linear theory, I will show the contamination induced by the relativistic bispectrum on the constraints of primordial non-gaussianity. I will also briefly discuss how to extend relativistic perturbation theory to higher order to describe 2-point statistics on smaller scales.