# Algebra and Algebraic Geometry Seminar Fall 2020

The Virtual Seminar will take place on Fridays at 2:30 pm via Zoom. We will also link to relevant or interesting Zoom talks outside of the seminar.

## Contents

## Algebra and Algebraic Geometry Mailing List

- Please join the AGS Mailing List to hear about upcoming seminars, lunches, and other algebraic geometry events in the department (it is possible you must be on a math department computer to use this link).

## COVID-19 Update

As a result of Covid-19, the seminar for this semester will be held virtually.

## Fall 2020 Schedule

date | speaker | title | host(s) |
---|---|---|---|

September 14 | Andrei Căldăraru (Madison) | Categorical Enumerative Invariants | Series of 4 lectures at Imperial College |

October 7 | Shamgar Gurevich (Madison) | TBD |

## Abstracts

### Andrei Căldăraru

**Categorical Enumerative Invariants**

I will talk about recent papers with Junwu Tu, Si Li, and Kevin Costello where we give a computable definition of Costello's 2005 invariants and compute some of them. These invariants are associated to a pair (A,s) consisting of a cyclic A∞-algebra and a choice of splitting s of its non-commutative Hodge filtration. They are expected to recover classical Gromov-Witten invariants when A is obtained from the Fukaya category of a symplectic manifold, as well as extend various B-model invariants (solutions of Picard-Fuchs equations, BCOV invariants, B-model FJRW invariants) when A is obtained from the derived category of a manifold or a matrix factorization category.

Series of 4 talks at Imperial College.

### Shamgar Gurevich

**TBD**

Talk in Sydney, Australia.