Speaker: Yusuke Taki (YITP, University of Kyoto)
Title: The semi-classical saddles in three-dimensional gravity via holography and mini-superspace approach
Abstract: We determine the complex geometries dual to the semi-classical saddles in three-dimensional gravity with positive or negative cosmological constant. We examine the semi-classical saddles in Liouville field theory and interpret them in terms of gravity theory. For this, we describe the gravity theory by Chern Simons theory and classify the possible saddles based on the winding number. We further realize the semi-classical saddles using the mini-superspace model of quantum gravity and explicitly determine the integral contour. In the case of positive cosmological constant, we recovered the geometry used for no-boundary proposal of Hartle and Hawking. In the case of negative cosmological constant, the geometry can be identified with Euclidean anti-de Sitter space attached with imaginary radius spheres. The geometry should be unphysical and several arguments on this issue are provided.
Date & Time: 3:00 PM, May 8, 2024.