# Panel Discussion of "Chern-Simons Terms" which Appear in the Action Principles of Theoretical Physics on the Occasion of Jim Simons' 85^{th} Birthday

The meeting will be held on Tuesday, April 25, 2023 at the CUNY Graduate Center (5^{th} Ave. & 34^{th} St.) in the Skylight Conference Room (9^{th} floor), between 2:00pm - 6:00pm plus. There will also be a banquet at the Century Club (near 5^{th} Ave. & 43^{th} St.) at 6:30pm.

## Why Chern-Simons Terms?

This will be a different sort of gathering to discuss the following question:

What are the so called "Chern-Simons Terms” which arose from differential geometry and what are their properties that suggest why they are used in Physics discussions?

This question was suggested by Jeff Cheeger whose work with Jim Simons led to the first framework, "Differential Characters" (1970s) for the initial "Chern-Simons term" constructed by Simons.

One motivation for this question is to aid the mathematically minded to understand something related to physics. This, in terms of structural ideas mathematicians can formulate, understand and then use.

The discussion might also benefit the physically minded by illustrating the ways of basic thinking that help many mathematicians to understand anything using mathematical structures quite forcefully.

The intended form of the gathering will be an open discussion front and center with a panel of mathematicians and physicists, with no lectures per se, but perhaps a blackboard for brief explanations. There will be a filmed interview of Jim conducted by Jean Pierre Bourguignon about the story of differential geometry questions that started the discussion leading to the first "Chern-Simons Term".

There will also be a showing of a short ten-minute film containing Jim reading the text of a fictional cosmology fantasy he wrote called "The last three minutes."

For registration, please click the following link:

## Panelists

### Physicists

Zohar Komargodski (Simons Center for Geometry and Physics (SCGP))

Juan Maldacena (Institute for Advanced Study (IAS))

Nikita Nekrasov (SCGP)

Cumrun Vafa (Harvard University)

Edward Witten (IAS)

### Mathematicians

Jean-Pierre Bourguignon (Former Director of IHES)

Simon Donaldson (SCGP & Imperial College London)

Alexander Kirillov (SUNY Stony Brook)

Dennis Sullivan (CUNY Graduate Center and SUNY Stony Brook)

Mahmoud Zeinalian (CUNY Graduate Center)

## Organization

Dennis Sullivan with the scientific help of Tony Phillips, Jeff Cheeger, Dan Freed, Mike Hopkins, Kevin Costello, Martin Rocek, the panelists and the technical support of Bora Ferlengez and Karen Marinez at the Grad Center.