26th APCTP Winter School on Fundamental Physics

Schedule

Lecturers

  • Prof. Kantaro Ohmori (University of Tokyo)
  • Title: Topological Aspects of Symmetry in Low Dimensions
  • References:
    • Lecture note by Kantaro Ohmori (will be updated during the school)
    • Notes by Yuji Tachikawa: the first half of Yuji’s lecture is about the big framework the most of researchers assume (but not necessarily proven), which I will omit. The second half of Yuji's will serve as an advanced version of this lecture.
    • Notes by Edward Witten: Not many overlap with this lecture but a good entry point to the field I think.
  • Abstract: In this lecture we will study the symmetry and its anomaly in low-dimensional, i.e. 0+1d and 1+1d, quantum field theories. In 0+1-dimensional quantum field theory, a.k.a quantum mechanics, the Wigner’s theorem tells that a global symmetry forms a group and acts on the Hilbert (state) space as a projective representation. We will see example with non-trivial projective phases and how it can be related to symmetry protected topological phases in 1+1-dimensions. We then see how the story are generalized/changed in 1+1-dimensional (relativistic) quantum field theory, where the locality of the theory plays an important role. Time permits, we also see how the inclusion of fermions affects the story.

Contact

  • Keun-Young Kim (fortoe@gist.ac.kr)