I will talk about the recent quite interesting article by Maldacena, in which he writes on the subject of the traversable wormholes. The most interesting thing that needs to be pointed out here are the way that wormholes are stabilised without the addition of the exotic matter while the theory that describes them is still Einstein gravity, with Maxwell theory and charged massless fermion, since wormholes without the addition of the exotic matter have been known in the higher derivative theories. The wormhole is made possible by fermions that give rise to negative Casimir-like energy and by being a long wormhole which does not lead to causality violations. https://arxiv.org/abs/1807.04726

We compute the heat kernel for the Laplacians of symmetric transverse traceless fields of arbitrary spin on the AdS background in even number of dimensions using the group theoretic approach and apply it on the partition function of six dimensional conformal gravity. The obtained partition function consists of the Einstein gravity, conformal ghost, partially massless mode and massive mode.