# Past Events

### Gabor Csanyi

University of CambridgeA foundational atomistic model for materials

April 15, 2024

ESB 1012

A new computational task has been defined and solved over the past 15 years for extended material systems: the analytic fitting of the Born-Oppenheimer potential energy surface as a function of nuclear coordinates. The resulting potentials ("force fields") are reactive, many-body, with... Read more

### Miguel Moreira

MITThe cohomology ring of moduli spaces of 1-dimensional sheaves on the projective plane

April 15, 2024

The cohomology of moduli spaces of 1-dimensional sheaves, together with a special filtration called the perverse filtration, can be used to give an intrinsic definition of (refined) Gopakumar-Vafa invariants. While there are methods to calculate the Betti numbers of these moduli spaces in low... Read more

- Intercontinental Moduli and Algebraic Geometry Seminar

### Benjamin Anderson-Sackaney

University of SaskatchewanFrom Groups to Quantum Groups and Their Operator Algebras

April 12, 2024

ESB 1012 (PIMS building)

Every group admits a faithful unitary representation on some Hilbert space. In other words, every group can be realized concretely as symmetries on a Hilbert space. From these representations we can construct certain operator algebras known as C*-algebras. These group C*-algebras enable an... Read more

### Ling Long

Louisiana State UniversityHypergeometric functions through the arithmetic kaleidoscope

April 11, 2024

ESB 4133

The classical theory of hypergeometric functions, developed by generations of mathematicians including Gauss, Kummer, and Riemann, has been used substantially in the ensuing years within number theory, geometry, and the intersection thereof. In more recent decades, these classical ideas have... Read more

- Number Theory

### Alexander Zimin

MITInequalities in Graph Percolation

April 10, 2024

Percolation on a graph is a random process that divides the edges into two groups: open and closed. Events such as "vertices v and w are connected via a path of open edges" occur within this process. We investigate the dependencies between these events and inequalities concerning their... Read more

- Probability

### Sarafa Adewale Iyaniwura

A multiscale mathematical model of chronic hepatitis B virus infection

April 10, 2024

PIMS Lounge ESB 4133

As the search for a cure for chronic hepatitis B virus infection continues, pharmaceutical companies have developed antivirals that target different stages of the intracellular life cycle of the virus. Earlier developed drugs such as pegylated interferon and nucleos(t)ide analogues (NAs) have... Read more

### Yibo Gao

Peking UniversityQuantum Bruhat graphs and tilted Richardson varieties

April 9, 2024

The quantum Bruhat graph is introduced by Brenti-Fomin-Postnikov to study structure constants of the quantum cohomology ring of the flag variety, with very rich combinatorial structures. In this talk, we provide an explicit formula for the minimal degree appearing in the quantum product of any... Read more

- Discrete mathematics

### James Carrell

UBCVector fields and cohomology

April 8, 2024

MATH 126

In this expository talk, let X be a smooth complex projective variety and V a holomorphic vector field on X such that 0 < |zero(V)| < \infty. Then the cohomology algebra H*(X) over C can be recovered from local data near the zero scheme Z of V. More precisely, when the upper triangular... Read more

- Algebra and Algebraic geometry

### Rachel Greenfeld

School of Mathematics of the Institute for Advanced StudyTiling, Sudoku, Domino, and Decidability

April 5, 2024

ESB 1012 (PIMS building)

Translational tiling is a covering of a space (such as Euclidean space) using translated copies of one building block, called a "translational tile'', without any positive measure overlaps. Can we determine whether a given set is a translational tile? Does any translational tile admit a periodic... Read more

### Hannah Keese

UBCActive learning in the math majors sections of matrix algebra and multivariable calculus

April 5, 2024

Math 225

I will discuss my implementation of active learning methods in the math majors sections of matrix algebra (Math 221) and multivariable calculus (Math 200), covering some examples of the course materials I used, the students' response to the learning methods, and outcomes from the semester. I... Read more