May 22 – 23, 2021
US/Eastern timezone

This is an online (zoom) workshop on "decomposition," which states that two-dimensional QFTs with finite global 1-form symmetries are equivalent to disjoint unions of QFTs without 1-form symmetries.  Decomposition was first described in hep-th/0606034, to understand properties of 2d continuum theories with finite 1-form symmetries such as the CP^n model with nonminimal charges, as originally described in hep-th/0502027, 0502044, 0502053.

Speakers will include

  • H-H Tseng (Ohio State University), on his and his collaborators' work from 2008 onwards on applications to Gromov-Witten invariants of gerbes, see for example arXiv:0812.4477, 0907.2087,
  • Mauricio Romo (Tsinghua) on applications to gauged linear sigma models (GLSMs).  One of the original applications of decomposition was to understand phases of certain GLSMs, where locally there is a finite 1-form symmetry which leads to a (nonperturbative) description as a branched cover (arXiv:0709.3855). Mauricio will discuss current developments, as in his paper arXiv:2012.14109.
  • Richard Eager (KIAS), on his recent work (arXiv:2009.03907) on elliptic genus computations in supersymmetric two-dimensional gauge theories and the role of decomposition,
  • Daniel Robbins (SUNY Albany), on his recent work (arXiv:2101.11619) on generalizations of decomposition in orbifolds,
  • Yuya Tanizaki (Yukawa Inst. Kyoto), on analogues of decomposition in four-dimensional gauge theories with three-form symmetries (arXiv:1912.01033),
  • Theodore Jacobson (Univ. Minnesota) on his recent work on vacua in universes (arXiv:2012.10555),
  • Zohar Komargodski (SUNY Stony Brook), on his recent work (arXiv:2008.07567) and its role in decomposition.

The schedule has been posted; all times are US eastern time.  We intend to record video, so that participants can watch asynchronously.

Registration is now open.  We ask that anyone who wishes to participate register in advance (use the registration link on this website).  We will send out zoom links a few days before the workshop beings to all registered participants. 


Code of conduct:  This event is committed to providing a harassment-free conference experience for everyone, regardless of race, ethnicity, gender, gender identity and expression, age, sexual orientation, disability, physical appearance, body size, religion or lack thereof. We do not tolerate harassment of event participants in any form in any event venue, including any online media.  Participants violating these rules may be sanctioned or expelled from the event.


Application for this event is currently open.