28 July 2024 to 3 August 2024
Europe/London timezone

$\eta$ invariant of massive Wilson Dirac operator and the index

30 Jul 2024, 11:35
20m
Talk Theoretical Developments Theoretical developments

Speaker

Hidenori Fukaya (Osaka Univ.)

Description

We mathematically show an equality between the index of a Dirac operator on a flat continuum torus and the $\eta$ invariant of the Wilson Dirac operator with a negative mass when the lattice spacing is sufficiently small. Unlike the standard approach, our formulation using the $K$-theory does not require the Ginsparg-Wilson relation or the modified chiral symmetry on the lattice. We prove that a one-parameter family of continuum massive Dirac operators and the corresponding Wilson Dirac operators belong to the same equivalence class of the $K^1$ group at a finite lattice spacing. Their indices, which are evaluated by the spectral flow or equivalently by the $\eta$ invariant at finite masses, are proved to be equal.

Primary authors

Shoto Aoki (The University of Tokyo) Hidenori Fukaya (Osaka Univ.) Prof. Mikio Furuta (U. of Tokyo) Prof. Shinichiroh Matsuo (Nagoya Univ.) Tetsuya Onogi (Osaka University) Prof. Satoshi Yamaguchi (Osaka Univ.)

Presentation materials