Large scale structure observables in a relativistic framework

In this seminar, I will give an overview of my field of research and I will discuss a few topics I am currently working on. In the near future, cosmology will benefit from a vast increase in the available data and it is of crucial importance to accurately model the quantities that will be observed from future surveys. In a fully relativistic framework, there are several additional contributions to the large scale structure (LSS) observables, beyond density perturbations and redshift space distortions. They are the so-called relativistic effects and they are due to gravitational lensing, Doppler, Shapiro time-delay and integrated Sachs-Wolfe effects on the path of photons. After an introduction to the topic, I will discuss the perspective of detecting some of these effects in the cross-correlation between Lyman-alpha and quasars. In the second part of the seminar, I will focus on the weak-lensing observables. The standard weak-lensing map modeling is based on the following ingredients: Newtonian N-body simulations and ray tracing techniques, where the photons are assumed to move along the unperturbed geodesics when computing their deflection angle. I will discuss how the two approximations outlined above can be released by using a relativistic setting for both the N-body simulations and a non-perturbative geodesic propagation of light in the inhomogeneous Universe.