- Speaker:
**Tomoki Ozawa**(AIMR, Tohoku University) - Title: Topological band structure in quantum and classical systems
- Date/Time: 16:00-17:30, Friday, November 27, 2020

- Speaker:
**Nobuyuki Okuma**(YITP, Kyoto University) - Title: Topology and anomaly in non-Hermitian skin effects: from index theorem to monopole catalysis
- Date/Time: 16:00-17:30, Friday, December 4, 2020

- Speaker:
**Yosuke Kubota**(Shinshu University) - Title: Coarse geometry and operator algebra in condensed-matter physics
- Date/Time: 16:00-17:30, Friday, January 8, 2021

- Speaker:
**Yuan Yao**(RIKEN) - Title: Critical parafermionic systems - from bosonization to parafermionization
- Date/Time: 16:00-17:30, Friday, March 26, 2021
- Abstract: In this talk, we will discuss a Zk parafermionization and bosonization scheme for one-dimensional lattice models and field theories on a torus, starting from the conventional bosonization for k=2. The Zk parafermionization enables us to investigate the critical theories of parafermionic chains whose fundamental degrees of freedom are parafermionic, and we find that their modular covariance properties are unconventional in that their partition functions on a torus transform differently from any conformal field theory when k>2. Several concrete examples of lattice models will be discussed where parafermionic statistics can be manifested. This talk is based on the preprint: arxiv:2012.07529.

- Speaker:
**Mayuko Yamashita**(RIMS, Kyoto University) - Title: The classification problem of non-topological invertible QFT's and a physically motivated model for the Anderson duals
- Date/Time: 16:00-17:30, Friday, April 23, 2021
- Abstract: Freed and Hopkins conjectured that the deformation classes of non-topological invertible quantum field theories are classified by a generalized cohomology theory called the Anderson dual of bordism theories. The main difficulty of this problem lies in the fact that we do not have the axioms for QFT's. In this talk, I will explain the ongoing work to give a new approach to this conjecture. We construct a new, physically motivated model for the Anderson duals. This model is constructed so that it abstracts a certain property of invertible QFT's which physicists believe to hold in general. I will start from basic motivations for the classification problem, report the progress of our work and explain future directions. This is the joint work with Yosuke Morita (Kyoto, math) and Kazuya Yonekura (Kyushu, physics).

- Speaker:
**Hosho Katsura**(the University of Tokyo) - Title: The SU(N) Hubbard model: some rigorous results
- Date/Time: 16:00-17:30, Friday, May 21, 2021

- Speaker:
**Ryohei Kobayashi**(ISSP, the University of Tokyo) - Title: Anomalies in (2+1)d fermionic topological phases and (3+1)d path integral state sums for fermionic SPT phases
- Date/Time: 16:00-17:30, Friday, June 25, 2021

- Speaker:
**Minkyu Kim**(the University of Tokyo) - Title: Toric code induced by bicommutative Hopf algebras
- Date/Time: 16:00-17:30, Friday, July 30, 2021

- Speaker:
**Yoshimasa Hidaka**(KEK) - Title: Higher group symmetry in axion electrodynamics
- Date/Time: 16:00-17:30, Friday, September 17, 2021

- Speaker:
**Shuhei Oyama**(YITP, Kyoto University) - Title: Generalized Thouless Pump and the Matrix Product State (video)
- Date/Time: 16:00-17:30, Friday, November 19, 2021

- Speaker:
**Chris Bourne**(Tohoku University) - Title: Fermionic gapped ground states and topological phases in the infinite volume limit
- Date/Time: 16:00-17:30, Friday, December 17, 2021

- Speaker:
**Kazuya Yonekura**(Tohoku University) - Title: Classification of topologically nontrivial terms in action
- Date/Time: 16:30-18:00, Friday, January 21, 2022