Claremont Topology Seminar

Founded 1989


The Claremont Topology Seminar meets in person on Tuesdays from 4:00pm-5:00pm in Fletcher 104 in Fall 2025 at the Pitzer College Campus of the Claremont Colleges. Fletcher Hall 104 faces the Scott Courtyard (Academic Quad) near Mills Avenue. Click HERE for a map of the Pitzer Campus.

Parking on Claremont Boulevard or College Avenue is free.


For more information about the Seminar, to suggest speakers, or to volunteer to speak, contact Bahar Acu, Dave Bachman, Sam Nelson, Vin de Silva, or Helen Wong

Fall 2025 Schedule (on semi-hiatus)

special days, times or locations are in purple

Date Speaker Title and Abstract
Tuesday

September 9

Organizational Meeting
4:00 PM at CK Tea House (109 N Yale Ave, Claremont, CA 91711)
Tuesday

September 16

No Meeting on hiatus

Tuesday

September 23

No Meeting on hiatus

Tuesday

September 30

No Meeting on hiatus

Tuesday

October 7

No Meeting on hiatus

Tuesday

October 14

No Meeting Fall Break
Tuesday

October 21

Puttipong Pongtanapaisan

Pitzer College

Title: Special Positions of Shapes in Four-Dimensional Space

Abstract: I will begin by convincing you that four-dimensional space is more familiar than it might first appear. Then, I will introduce ways in which mathematicians study objects in 4-space. Each visualization method comes with its own advantages and limitations, as well as a natural measure of complexity that captures how "knotted" a shape can be. Drawing from my work on several projects, I will explain how these complexity measures connect to other areas of mathematics. For example, placing surfaces in what we call a rainbow position reveals connections to symplectic geometry.

Tuesday

October 28

No Meeting on hiatus

Tuesday

November 4

Robert Cass

Claremont McKenna College

Title: Schubert varieties are splinters

Abstract: Schubert varieties are among the most well-studied singular algebraic varieties, and they have numerous applications in combinatorics and representation theory. In positive characteristic, Schubert varieties are known to be Frobenius split by the work of Mehta and Ramanathan. More recently, Bhatt showed that the full flag variety for GL_n is a derived splinter by entirely different methods. In this talk, we explain these concepts and we show how to generalize Bhatt's result to all Schubert varieties. Our methods apply equally well to affine Schubert varieties, which are of interest in number theory. This is joint work with Joao Lourenco.

Tuesday

November 11

No Meeting on hiatus

Tuesday

November 18

Chris Grossack

UC Riverside

Title: Explicitly Computing Fukaya Categories of Surfaces

Abstract: Fukaya categories are rich and interesting invariants of symplectic manifolds that are often difficult to compute in practice. In the case of surfaces, however, the computation becomes pleasantly combinatorial, and can be carried out explicitly. In this expository talk we'll explain why one might care about Fukaya categories and how one can compute them explicitly enough for computer implementation using tools from "Noncommutative Mirror Symmetry". With any remaining time we'll explain the ideas behind the speaker's PhD thesis, which relies heavily on this machinery.

Tuesday

November 25

No Meeting Thanksgiving Week
Tuesday

December 2

Indraneel Tambe

UCLA

Title: Steinberg skein relations at roots of unity

Abstract: This talk discusses some of the relationships between skein theory and the representation theory of quantum sl2 when q is a root of unity. Specifically, I focus on the Frobenius pullback functor on Uq sl2 representations and see how this relates to Bonahon-Wong's Frobenius skein homomorphism between Kauffman bracket skein modules. I'll describe results from my joint work with Vijay Higgins in which we proved what we called Steinberg skein identities and used these in a new proof of the well-definition of the Frobenius skein homomorphism.


Archived Schedules

2024-2025

2023-2024

2022-2023

2018-2019

2017-2018

2016-2017

2015-2016

2014-2015

2013-2014

2012-2013

2011-2012

2010-2011

2009-2010

2008-2009

2007-2008

2006-2007

2005-2006

2004-2005

2003-2004


This site is maintained by Bahar Acu who received the (33yo) baton from Jim Hoste in 2022.