Speaker
Description
In this talk we discuss a systematic analysis to extract the asymptotic behaviour of perturbative contributions to observables in power-law FRW cosmologies, indistinctly the cosmological wavefunction and correlators, as well as one loop corrections to the wavefunction. The perturbative contributions to an observable can be expressed as an integral of the canonical function associated to cosmological polytopes. We discuss how the asymptotic behaviour of these integrals is governed by a special class of nestohedra living in the graph-weight space, both at tree and loop level. We will show the realization of these nestohedra and how they can inform us about all the possible directions (IR and UV), where the integral can diverge as well as their degree of divergence. Then, we will show how this combinatorial formulation makes straightforward the application of sector decomposition for extracting divergences from the integral.
Finally, we will discuss corrections to the one loop wavefunction.
