Euclidean axion wormholes in de Sitter space

In this talk, I’ll present work in progress on the properties of Euclidean wormholes supported by axion flux in de Sitter space. The corresponding geometry describes a handle attached to the Euclidean sphere. We compute the on-shell action and verify perturbative stability. Unlike Euclidean axion wormholes in flat or AdS space, the de Sitter embedding allows for a clear understanding thanks to the quantum cosmological setup where wormholes describe no-boundary probabilities to nucleate de Sitter universes with axion flux threading the spacelike slice. The wormhole size and axion flux is bounded and the largest wormhole ("Nariai" wormholes) corresponds to the nucleation of a de Sitter universe with critical axion density.