UC Santa Cruz

There has been a resurgence of interest in wormholes, and continued growth in the study of primordial black holes, opening up new questions about these objects and their possible existence in our universe. Recent papers demonstrate a new way of forming wormholes in the early universe, via collapsing inflationary bubbles. On our end, these wormholes would take the form of primordial black holes. This lends new interest to an intriguing and largely unaddressed question of what happens to a wormhole as the black hole on each end of it Hawking evaporates. Primordial wormholes would have an early period of traversability and we find, using calculations based on a semi-classical model of Hawking radiation, that as they evaporate they become traversable again to some degree. They then could evaporate to leave a Planck-size wormhole that may or may not persist. We also explore the implications of traversable wormholes and the questions that arise from their existence.