**Date**: 2021.10.29**Place**: 129-101

**Speaker**: 박지훈 (2시~3시)**TiTle**: Quantum entanglement entropy in abelian arithmetic Chern-Simons theory**Abstract :**Arithmetic Chern-Simon theory is an example of topological quantum field theory which is developed based on the analogy between knots (in topology) and primes (in number theory).

In this talk, I will explain a basic set-up of the theory when the gauge group is a finite group (called Dijkgraaf-Witten theory), which has a benefit that there is no convergence issue in the corresponding Feynman path integral.

In particular, I will explain how to construct the Feynman path integral in arithmetic DW theory as an element of a quantum Hilbert space and introduce a notion of its entanglement entropy.

When the gauge group is finite cyclic of prime order, I will provide an explicit computation of entanglement entropy of the Feynman path integral of a certain number field

This talk is based on ongoing joint work with Hee-Jung Chung, Dohyeong Kim, Minhyong Kim, and Hwajong Yoo.

- Speaker : 김유식 (4시~5시)
- Title : Exotic monotone Lagrangian tori in flag varieties.
- Abstract : In this talk, I will describe the background of classification problems of monotone Lagrangian tori and explain how to construct them in flag varieties.