Spring 2026

Mathematics Colloquium

Location and Time: Minard 310 at 3:00 PM (Refreshments at 2:30 in Minard 404)

*Special Colloquia or Tri-College Colloquia venues and times may vary, please consult the individual listing.

Tuesday, February 10

Pranav Arrepu, UC Santa Barbara

Recovery of Coefficients in Nonlinear Schrödinger Equations by Carleman Estimates

Abstract: We consider a class of dynamical Schrödinger equations with locally analytic nonlinear terms on a smooth bounded domain and take up the inverse problem of recovering the linear potential and nonlinear interaction coefficients. Assuming the coefficients are known in a given neighborhood of the boundary, we establish unique and stable determination by measurements of the Neumann data on an arbitrary part of the boundary. Our proof relies on a transformation to an associated linear parabolic equation along with a direct application of Carleman estimates for the linear parabolic and Schrödinger equations. This is joint work Hanming Zhou.

Tuesday, February 24

Bridget Tenner, DePaul University

Majority relations: how do ranked ballots shake out?

Abstract: Suppose you have an election in which each voter ranks the full slate of candidates. If we want to draw an aggregated conclusion from all of the ballots cast, what is the "winning" candidate ranking? We will study this question on so-called Condorcet domains of tiling type, which can be defined in terms of rhombic tilings of certain polygons (equivalently, in terms of reduced decompositions of permutations). We can then use heaps and poset theory to show important properties of the majority relation in these domains. We will demonstrate these results by computing the majority relation explicitly for several important classes.

This talk is based on joint work with Vic Reiner.

Tuesday, March 3

Azer Akhmedov, NDSU

TBD

Abstract: TBD

Tuesday, April 7

*Special Tri-College Colloquium at Concordia
Talk: Integrated Science Center 301 (Refreshments: Integrated Science Center 362)

Jessica Striker, NDSU

Title: TBD

Abstract: TBD

Thursday, April 16

Allison Byars, U of Wisconsin

TBD

Abstract: TBD