Quantum Entanglement of Baby Universes

TL;DR

This paper explores quantum entanglement among baby universes in string theory, revealing their superposition, charge conservation, and stability properties, extending previous results to more complex topologies.

Contribution

It generalizes the entanglement analysis of baby universes to arbitrary genus Riemann surfaces in Type IIA string theory, incorporating non-perturbative effects into the OSV entropy formula.

Findings

Baby universes form a superposed wave-function in third quantization.

Half of the universes preserve one set of supercharges, the other half another, making the total universe stable but non-BPS.

Baby universes are correlated through conserved D-brane charges.

Abstract

We study quantum entanglements of baby universes which appear in non-perturbative corrections to the OSV formula for the entropy of extremal black holes in Type IIA string theory compactified on the local Calabi-Yau manifold defined as a rank 2 vector bundle over an arbitrary genus G Riemann surface. This generalizes the result for G=1 in hep-th/0504221. Non-perturbative terms can be organized into a sum over contributions from baby universes, and the total wave-function is their coherent superposition in the third quantized Hilbert space. We find that half of the universes preserve one set of supercharges while the other half preserve a different set, making the total universe stable but non-BPS. The parent universe generates baby universes by brane/anti-brane pair creation, and baby universes are correlated by conservation of non-normalizable D-brane charges under the process. There are no other source of entanglement of baby universes, and all possible states are superposed with the equal weight.