Abstract
Abstract
As shown by Louko and Sorkin in 1995, topology change in Lorentzian signature involves spacetimes with singular points, which they called crotches. We modify their construction to obtain Lorentzian semiclassical wormholes in asymptotically AdS. These solutions are obtained by inserting crotches on known saddles, like the double-cone or multiple copies of the Lorentzian black hole. The crotches implement swap-identifications, and are classically located near an extremal surface. The resulting Lorentzian wormholes have an instanton action equal to their area, which is responsible for topological suppression in any number of dimensions.We conjecture that including such Lorentzian wormhole spacetimes is equivalent to path integrating over all mostly Euclidean smooth spacetimes. We present evidence for this by reproducing semiclassical features of the genus expansion of the spectral form factor, and of a late-time two point function, by summing over the moduli space of Lorentzian wormholes. As a final piece of evidence, we discuss the Lorentzian version of West-Coast replica wormholes.
Publisher
Springer Science and Business Media LLC
Subject
Nuclear and High Energy Physics
Reference97 articles.
1. S. Coleman, J.B. Hartle, T. Piran and S. Weinberg, Quantum Cosmology And Baby Universes. Vol. 7: Proceedings Of 7th Jerusalem Winter School for Theoretical Physics, World Scientific (1991).
2. T. Anous, J. Kruthoff and R. Mahajan, Density matrices in quantum gravity, SciPost Phys. 9 (2020) 045 [arXiv:2006.17000] [INSPIRE].
3. E. Casali, D. Marolf, H. Maxfield and M. Rangamani, Baby universes and worldline field theories, Class. Quant. Grav. 39 (2022) 134004 [arXiv:2101.12221] [INSPIRE].
4. D. Marolf and H. Maxfield, Transcending the ensemble: baby universes, spacetime wormholes, and the order and disorder of black hole information, JHEP 08 (2020) 044 [arXiv:2002.08950] [INSPIRE].
5. S.R. Coleman, Black Holes as Red Herrings: Topological Fluctuations and the Loss of Quantum Coherence, Nucl. Phys. B 307 (1988) 867 [INSPIRE].