The cosmohedron was recently proposed as a polytope underlying the cosmological wavefunction for Tr(phi^3) theory. Its faces were conjectured to be in bijection with Matryoshkas, which are obtained from a subdivision of a polygon by sequentially wrapping groups of polygons into larger polygons. We prove the correctness of this construction, and elucidate its combinatorial structure.
This is joint work with Nima Arkani-Hamed, Carolina Figueiredo, and Francisco Vazão.