The Asymptotic Structure of Cosmological Integrals

In this talk, we discuss a systematic analysis to extract the asymptotic behaviour of perturbative contributions to observables (wavefunction and correlators) in power-law FRW cosmologies. 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 realisation of these nestohedra and how they can inform us about all the possible directions (IR and UV), in which the integral can diverge. Finally, we will show how this combinatorial formulation makes straightforward the application of sector decomposition for extracting divergences from the integral.

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