Title: Perturbative Nonlinearities in the Structure Formation of the Universe

Abstract: I will discuss recent developments in cosmological perturbation theory and the effective field theory (EFT) of large-scale structure. Current galaxy surveys like DESI and Euclid provide some of the cleanest probes of the universe on large cosmological scales. While the one-loop power spectrum (the two-point correlator) remains the standardised and widely adopted theoretical tool, fully exploiting the potential of these new datasets requires extending our theoretical framework to higher loops and N-point correlators. I will outline the theoretical and computational challenges involved in going beyond the one-loop level and present recent results in the context of DESI and forthcoming Euclid data.