Nava will give a talk entitled “The Hilbert space of baby universes”, based on 1807.00824 and 2004.06738, with the following abstract:

Abstract: I will review what \alpha parameters of Coleman's baby universes are and McNamara-Vafa's argument that they belong in the swampland. Then, I will explain their "Baby universe hypothesis" that the Hilbert space of baby universes is trivial (of dimension one).

Finally, I will argue why this hypothesis is too simplistic. I will propose how non-trivial states can be built out of the "void"/vacuum in the said Hilbert space and argue that this is consistent with Coleman's alpha parameters belonging in the swampland. Incidentally, our proposal means that the Cobordism conjecture that Stefano explained to us last week is also too strong. This is based on my soon-to-appear work (with P. Betzios and O. Papadoulaki).

Suggested papers: