Seminars and Colloquia by Series

Canceled

Series
Analysis Seminar
Time
Wednesday, October 14, 2026 - 14:00 for 1 hour (actually 50 minutes)
Location
Skiles 005
Speaker
Emily Casey – University of Minnesota –

Ruilin Shi, TBA

Series
Graph Theory Seminar
Time
Tuesday, October 13, 2026 - 15:45 for 1 hour (actually 50 minutes)
Location
Skiles 005
Speaker
Ruilin Shi – Duke University

TBA

TBA by Gilbert Weinstein

Series
PDE Seminar
Time
Monday, October 12, 2026 - 14:00 for 1 hour (actually 50 minutes)
Location
Piedmont room (John Lewis Student Center)
Speaker
Gilbert Weinstein – Ariel University

TBA

Computing the fractional Dehn twist coefficient of braids using non-crossing partition diagrams

Series
Geometry Topology Seminar
Time
Monday, October 12, 2026 - 14:00 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker

The dual Garside left canonical form is used to solve the conjugacy problem in braid theory, introduced by Xu (3-braids), Kang-Ko-Lee (4-braids) and Birman-Ko-Lee (n-braids). The fractional Dehn twist coefficient (FDTC) is a measurement of the boundary twist of a surface homeomorphism, introduced by Honda-Kazez-Matic. In contact geometry, it is a powerful tool to detect tightness/overtwistedness of a given contact structure. In this talk, I will give applications of the left canonical form to the computation of the FDTC of 4-braids.

Reciprocal Discriminants

Series
Combinatorics Seminar
Time
Friday, October 9, 2026 - 15:15 for 1 hour (actually 50 minutes)
Location
Skiles 005
Speaker
Frank Sottile – Texas A&M University –

Motivated by applications and the classical theory of A-discriminants of Gel'fand, Kapranov, and Zelevinsky, we develop the basic theory of discriminants of multivariate reciprocal polynomials. These reciprocal discriminants parameterize reciprocal polynomials that define a singular hypersurface. We show that a reciprocal discriminant has a rich combinatorial structure. It is a reducible hypersurface whose components are dual varieties to Chebyshev subvarieties which correspond to certain layers in a toric arrangement associated to the exponents of the reciprocal polynomials. The layers which contribute correspond to certain matroidal decompositions of the exponents.

This is joint work with Trevor Karn and Simon Telen.

Pages