DEPARTMENT OF PHYSICS DISSERTATION: Cynthia Yan

Ph.D. Candidate:  Cynthia Yan

Research Advisor:  Douglas Stanford

Date:  Wednesday, April 30, 2025 

Time:  1:30 pm PT

Location: Varian Building, room 355

Zoom link:   https://stanford.zoom.us/j/97508763053

Email physicsstudentservices [at] stanford.edu (physicsstudentservices[at]stanford[dot]edu) for password.

Title:   Exploring Low Dimensional Quantum Gravity as a Topology Enthusiast

Abstract:  Quantum gravity, which seeks to unify general relativity and quantum mechanics, is vital for addressing fundamental physics problems. AdS/CFT correspondence is a significant advance in this pursuit. Low dimensional quantum gravity is a laboratory for studying quantum gravity which doesn’t have the complications due to non-renormalizability in higher dimensions, yet captures the universal aspects of black holes at low temperature. These dualities are different from earlier examples of AdS/CFT in that the boundary side is an ensemble of quantum theories. 

In this talk, I will present the main results of my recent work Puzzles in 3D Off-Shell Geometries via VTQFT. We point out a difficulty with a naive application of Virasoro TQFT methods to compute path integrals for two types of off-shell 3-dimensional geometries. Maxfield-Turiaci proposed solving the negativity problem of pure 3d gravity by summing over off-shell geometries known as Seifert manifolds. We attempt to compute Seifert manifolds using Virasoro TQFT. Our results don't match completely with Maxfield-Turiaci. We trace the discrepancies to not including the mapping class group properly. We also compute a 3-boundary torus-wormhole by extrapolating from an on-shell geometry. We encounter challenges similar to those observed in the comparison between the genuine off-shell computation of a torus-wormhole by Cotler-Jensen and the extrapolation from an on-shell configuration.