# Past Events

### Lisa Fauci

Tulane UniversityWaving, 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 tissue for drug... Read more

### Magdalena Larfors

Uppsala UniversityStringy perspectives on manifolds with G2 structure

October 3, 2023

Zoom Talk

Seven-dimensional, real, Riemannian manifolds with G2 structure have interesting geometric properties. In this talk, I will discuss some of these aspects, and how they are probed by supersymmetric solutions of heterotic string theory. Read more

- Differential geometry
- Mathematical Physics
- Partial Differential Equations

### Georg Oberdieck

KTHCurve counting on the Enriques surface and the Klemm-Marino formula

October 2, 2023

An Enriques surface is the quotient of a K3 surface by a fixed point-free involution. Klemm and Marino conjectured a formula expressing the Gromov-Witten invariants of the local Enriques surface in terms of automorphic forms. In particular, the generating series of elliptic curve counts on the... Read more

- Intercontinental Moduli and Algebraic Geometry Seminar

### Liam Watson

UBCKhovanov multicurves are linear

September 29, 2023

MATX 1100

For a given invariant the geography problem asks for a characterization of values the invariant attains. For example, it is well understood which Laurent polynomials arise as the Alexander polynomial of a knot. By contrast, very little is known about which values the Jones polynomial takes. And... Read more

### Stephen Choi

Simon Fraser UniversityGap Principle of Divisibility Sequences of Polynomials

September 28, 2023

ESB 4133

Let $f \in \mathbb{Z}[x]$ and $\ell \in \mathbb{N}$. Consider the set of all $(a_{0},a_{1},\dots,a_{\ell}) \in \mathbb{N}^{\ell+1}$ with $a_{i} < a_{i+1}$ and $f(a_{i}) \mid f(a_{i+1})$ for all $0 \leq i \leq \ell-1$. We say that $f$ satisfies the gap principle of order $\ell$ if $\lim a_{\... Read more

- Number Theory

### Serte Donderwinkel

McGill UniversityRandom trees are short (but not too short)

September 27, 2023

I will discuss some new upper and lower bounds on the height of random trees. The first result is that, under very general assumptions, trees with a given degree sequence, simply generated trees and BienaymĂ©-Galton-Watson trees of size $n$ have height \( O(\sqrt{n}) \) with Gaussian tails (and... Read more

- Probability

### David Holloway

UBC BCITWhat conifer trees can show us about how organs are positioned in developing organisms

September 27, 2023

ESB 4133

One of the central questions in developmental biology is how organs form in the correct positions in order to create a functional mature organism. Plant leaves offer an easily observable example of organ positioning, with species-specific motifs for leaf arrangement (phyllotaxis). These patterns... Read more

- Mathematical Biology

### Mark Shoemaker

UBCCounting curves in determinantal varieties and a connection to quiver mutations

September 25, 2023

MATH 126

Suppose X is a smooth projective variety, E and F are vector bundles on X, and M: E â€”> F is a map of vector bundles. More concretely, M defines a family of matrices {M_x}, parametrized by the points x of the variety X. For a positive integer k, we can define the kth determinantal variety of M... Read more

- Algebra and Algebraic geometry

### Ben Krause

King's College LondonPointwise ergodic theory pre -Covid: Everything I knew about everything I knew that far

September 25, 2023

ESB 4133 (PIMS library)

I will survey the state of the art of pointwise ergodic theory before Covid, with an emphasis on the work of Bourgain. Read more

- Harmonic Analysis and Fractal Geometry

### Fanze Kong

UBCGlobal existence and aggregation of chemotaxis-fluid systems in dimension two

September 21, 2023

In-person talk in ESB 4133

To describe the cellular self-aggregation phenomenon, some strongly coupled PDEs named as Keller-Segel (KS) and Patlak-Keller-Segel (PKS) systems were proposed in 1970s. Since KS and PKS systems possess relatively simple structures but admit rich dynamics, plenty of scholars have studied them... Read more

- Differential geometry
- Mathematical Physics
- Partial Differential Equations