Seminars and colloquia

E.g., Oct 4, 2023

Lisa Fauci

Tulane University
Waving, rotating, buckling, flowing: adventures of filaments at the microscale

October 4, 2023

ESB 4133

The motion of undulating or rotating filaments in a fluid environment is a common element in many biological and engineered systems. Examples at the microscale include bacterial flagella propelling a cell body and engineered helical nanopropellers designed to penetrate mucosal ... Read more

Elchin Hasanalizade

ADA University (Azerbaijan)
On some explicit results for the sum of unitary divisor function

October 5, 2023

ESB 4133

Let $\sigma^*(n)$ be the sum of all unitary (i.e. coprime) divisors of $n$. As an analogue of Lehmer’s totient problem, Subbarao proposed the following conjecture. The congruence $\sigma^*(n)\equiv 1\pmod{n}$ is possible iff $n$ is a prime power. This problem is still open. We ... Read more
  • Number Theory

Sven Bachmann

The importance of counting eigenvalues: From solar radiation to the stability of matter

October 6, 2023

ESB 1012

The problem of counting the number of eigenvalues of a differential operator is exactly as old as quantum theory and was inspired by various physical questions. In the century since Weyl’s first asymptotic result on the topic, the question has inspired numerous mathematical ... Read more

Spiro Karigiannis

U Waterloo
Flows of G2 structures

October 10, 2023

In-Person Talk in ESB 4127

A G2-structure is a special type of 3-form on an oriented 7-manifold, which determines a Riemannian metric in a nonlinear way. The best class of such 3-forms are those which are parallel with respect to their induced Levi-Civita connections, which is a fully non-linear PDE. ... Read more
  • Differential geometry
  • Mathematical Physics
  • Partial Differential Equations

Emma Jin

Xiamen University
Symmetric generating functions, permutation statistics and basic hypergeometric series

October 10, 2023

ESB 4133

First, I will present a series of classical results on symmetric generating functions and permutation statistics, including the classical results by Carlitz, Roselle and Scoville (1966), by Garsia and Gessel (1978), by Gessel and Reutenauer (1993), etc. Second, I will focus on ... Read more
  • Discrete mathematics

Hermann Riecke

Northwestern University

October 11, 2023

ESB 4133

  • Mathematical Biology

Matthew Dickson

High-dimension expansion of the critical intensity of the random connection model

October 11, 2023

The random connection model (RCM) is a random graph model where the vertices are given by a Poisson point process with a given intensity, \(\lambda>0 \), and the edges exist independently with a probability that depends upon the relative positions of the two vertices in ... Read more
  • Probability

Mark Shoemaker

Colorado State
An introduction to the gauged linear sigma model

October 12, 2023

MATH 126

A Landau—Ginzburg model (Y, w) consists of a smooth complex variety Y together with a function w: Y—> C. Curve counting invariants have recently been defined for a large class Landau—Ginzburg models. The theory goes by the name of the gauged linear sigma model, and ... Read more
  • Algebra and Algebraic geometry

Kevin Ren

Discretized Radial Projections and Pinned Distances in R^d

October 16, 2023

ESB 4133 (PIMS library)

Given two sets X, Y in R^d, such that X isn't contained in a k-plane, we show that there exists a point x in X such that the radial projection pi_x (Y) has Hausdorff dimension > min(dim(X), dim(Y), k) - eps, for any given eps > 0. This improves a result of Orponen- ... Read more
  • Harmonic Analysis and Fractal Geometry

Anne Quéguiner-Mathieu

Université Paris 13 (Sorbonne Paris Nord)
Tate traces and classification of Chow motives

October 16, 2023

MATH 126

This talk is based on a joint work with Charles De Clercq. The main result is a classification theorem for some Chow motives with finite coefficients, which applies, notably, to motives of projective homogeneous varieties under some semi-simple algebraic groups. The result ... Read more
  • Algebra and Algebraic geometry