Talk page

Title:
Non-invertible time-reversal symmetry

Speaker:
Shu-Heng Shao

Abstract:
In gauge theory, it is commonly stated that time-reversal symmetry only exists at $\theta=0$ or $\pi$ for a $2\pi$-periodic $\theta$-angle. In this paper, we point out that in both the free Maxwell theory and massive QED, there is a non-invertible time-reversal symmetry at every rational $\theta$-angle, i.e., $\theta= \pi p/N$. The non-invertible time-reversal symmetry is implemented by a conserved, anti-linear operator without an inverse. It is a composition of the naive time-reversal transformation and a fractional quantum Hall state. We also find similar non-invertible time-reversal symmetries in non-Abelian gauge theories, including the $\mathcal{N}=4$ $SU(2)$ super Yang-Mills theory along the locus $|\tau|=1$ on the conformal manifold.

Link:
http://scgp.stonybrook.edu/video_portal/video.php?id=5453

Workshop:
Simons- Workshop: Generalized Global Symmetries, Quantum Field Theory, and Geometry