# Past Events

### Jeffrey Rosenthal

University of TorontoSpeeding up Metropolis using Theorems

February 22, 2024

ESB5104

Markov chain Monte Carlo (MCMC) algorithms, such as the Metropolis algorithm, are designed to converge to complicated high-dimensional target distributions, to facilitate sampling. The speed of this convergence is essential for practical use. In this talk, we will present several theoretical... Read more

- Probability

### Ertan Elma

University of LethbridgeA Discrete Mean Value of the Riemann Zeta Function and its Derivatives

February 15, 2024

ESB 4133

In this talk, we will discuss an estimate for a discrete mean value of the Riemann zeta function and its derivatives multiplied by Dirichlet polynomials. Assuming the Riemann Hypothesis, we obtain a lower bound for the 2kth moment of all the derivatives of the Riemann zeta function evaluated at... Read more

- Number Theory

### Naotaka Kajino

Kyoto UniversityOn singularity of p-energy measures among distinct values of p for some p.-c.f. self-similar sets

February 14, 2024

For each $p \in (1,\infty)$, a \emph{$p$-energy form} $(\mathcal{E}_{p},\mathcal{F}_{p})$, a natural $L^{p}$-analog of the standard Dirichlet form for $p=2$, was constructed on the (two-dimensional standard) Sierpi\'{n}ski gasket $K$ by Herman--Peirone--Strichartz [Potential Anal. **20**... Read more

- Probability

### Maksym Zubkov

UC Berkeley MathematicsGeometry of Principally Regular Matrices

February 14, 2024

IAM Lounge (LSK 306)

The space of real symmetric matrices whose principal minors are all non-zero is called a space of principally regular matrices. This space parametrizes the space of totally non-degenerate quadratic forms which are local models of ridgy Lagrangians introduced as a tool in the arborealization... Read more

### Marjolein Toorians

UBCBiodiversity loss and the rise of epidemics: Disease-emergence explained through host phylogenetic community structure

February 14, 2024

ESB 4133

Biodiversity loss worldwide coincides with an increase in epidemics. This loss of species and reassembly of species communities is thought to be connected to disease transmission via two, opposing, theories: (1) the dilution effect predicts that high species richness can buffer diseases, and... Read more

- Mathematical Biology

### Thomas Richard

Smallness of topologically rich manifolds with positive scalar curvature

February 13, 2024

ESB 4133

Let (M^n,g) be compact Riemannien manifold, it is a classical result that if (M^n,g) has Ricci curvature bigger thant the standard sphere, its volume and diameter are smaller than those of the sphere. If (M^n,g) only has scalar curvature bigger than that of the sphere, the diameter and volume... Read more

- Differential geometry
- Mathematical Physics
- Partial Differential Equations

### Lucas Mouline

Université de BourgogneReal forms of almost homogeneous SL2-threefolds

February 12, 2024

MATH 126

Given a complex algebraic variety X, a classical problem in algebraic geometry is to determine the real forms of X, where a real form is an algebraic variety Y which becomes isomorphic to X over the complex numbers. We are interested in a variant of this problem, in the case where X is a G-... Read more

- Algebra and Algebraic geometry

### Alex Rutar

University of St AndrewsAssouad dimension and tangents of dynamically invariant sets

February 12, 2024

ESB 4133 (PIMS library)

A tangent of a compact set is an accumulation point in Hausdorff distance given by 'zooming in' at a given point. For general compact sets, it is well-known that the Assouad dimension is characterized by dimensions of weak tangents (where the location of zooming in is allowed to change), but not... Read more

- Harmonic Analysis and Fractal Geometry

### Felix Thimm

University of OsloThe 3-fold K-theoretic DT/PT vertex correspondence

February 12, 2024

Donaldson-Thomas (DT) and Pandharipande-Thomas (PT) invariants are two curve counting invariants for 3-folds. In the Calabi-Yau case, a correspondence between the numerical DT and PT invariants has been conjectured by Pandharipande and Thomas and proven by Bridgeland and Toda using wall-crossing... Read more

- Intercontinental Moduli and Algebraic Geometry Seminar

### Amir Sagiv

TechnionFloquet Materials - a Dynamical Systems Approach

February 8, 2024

PIMS Lounge ESB 4133

The last decade has witnessed tremendous experimental progress in the study of "Floquet media", crystalline materials whose properties are altered by time-periodic parametric forcing. Theoretical advancements, however, have so far been achieved through discrete and approximate models.... Read more