# Gapped boundary theories for 3d Chern-Simons

### APA

Freed, D. (2019). Gapped boundary theories for 3d Chern-Simons. Perimeter Institute. https://pirsa.org/19090100

### MLA

Freed, Dan. Gapped boundary theories for 3d Chern-Simons. Perimeter Institute, Sep. 19, 2019, https://pirsa.org/19090100

### BibTex

@misc{ pirsa_PIRSA:19090100, doi = {10.48660/19090100}, url = {https://pirsa.org/19090100}, author = {Freed, Dan}, keywords = {Mathematical physics}, language = {en}, title = {Gapped boundary theories for 3d Chern-Simons}, publisher = {Perimeter Institute}, year = {2019}, month = {sep}, note = {PIRSA:19090100 see, \url{https://pirsa.org}} }

Harvard University

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Abstract

I will discuss a theorem, joint work in progress with Constantin Teleman, in which we characterize which topological 3-dimensional Chern-Simons theories admit nonzero boundary theories. Accepting some physical heuristics, it tells which gapped systems in 2+1 dimensions admit only gapless boundary systems.