Mathematics and Statistics trailblazer Felicia Magpantay (Department of Mathematics and Statistics) has earned one of the two 2024 Senator Tobias C. Enverga Jr. Medals of Excellence for demonstrating strong leadership and making significant contributions towards the betterment of their communities.
Date
Monday March 31, 2025Location
116 JEFFERY HALLMath & Stats Algebra & Geometry Seminar
Monday, March 31, 2025
Time: 4:30 p.m. Place: Jeffery Hall, Room 116
Speaker: Federico Galetto (Cleveland State University)
Title: Principal jets of monomial ideals
Abstract: The study of jets originates in differential geometry and has found applications to a range of topics from birational geometry to motivic integration. After showing how to construct the jets of an affine scheme, I will discuss connections with monomial ideals and combinatorics, specifically with clutters or simple hypergraphs. I will then present some results on principal jets of monomial ideals from joint work with Nicholas Iammarino and Teresa Yu.
Date
Monday March 24, 2025Location
116 JEFFERY HALLMath & Stats Algebra & Geometry Seminar
Monday, March 24, 2025
Time: 4:30 p.m. Place: Jeffery Hall, Room 116
Speaker: Patricia Klein (Texas A&M University)
Title: Algebra and geometry of ASM weak order
Abstract: The central objects of study in this talk will be Schubert varieties in the complete flag variety. These Schubert varieties are indexed by permutations, which we will identify with permutation matrices. Schubert varieties can be studied via affine varieties called matrix Schubert varieties, introduced by Fulton. One can associate an arbitrary intersection of matrix Schubert varieties to what is called an alternating sign matrix (ASM). In this talk, we will review the role of matrix Schubert varieties - and their unions and intersections - in Schubert calculus and describe classical uses of permutation matrices and strong Bruhat order in encoding algebro-geometric invariants. We will then describe new work giving relationships between algebro-geometric invariants of unions and intersections of matrix Schubert varieties and ASMs under weak Bruhat order. No prior knowledge of strong or weak Bruhat order will be assumed for this talk. This is joint work with Laura Escobar and Anna Weigandt.
Mathematics and Statistics Professor Thomas Barthelmé has earned an Alliance International grant from the National Sciences and Engineering Research Council of Canada (NSERC).
Date
Friday March 21, 2025Location
Jeffrey Hall, Room 234Math & Stats Department Colloquium
Friday, March 21, 2025
Time: 2:30 p.m. Place: Jeffery Hall, Room 234
Speaker: Cy Maor (Hebrew University of Jerusalem)
Title: Non-Euclidean Elasticity - From the Shapes of Leaves to (Almost) Isometric Immersions and Back
Abstract: Non-Euclidean elasticity concerns elastic bodies that are strained even in the absence of external forces. While its origins trace back to the 1950s, the field gained renewed attention in the 21st century as a framework for understanding the shapes of leaves, molecular structures, and other systems undergoing inhomogeneous growth. Mathematically, it studies the question of how to immerse 3D Riemannian manifolds in ℝ^3 "as isometric as possible" (in a precise sense). In this talk, I will introduce the model and discuss the mathematical questions it raises—some resolved, many still open. There will be pictures, there will be theorems, and, hopefully, even a live experiment.
Date
Monday March 17, 2025Location
116 JEFFERY HALLMath & Stats Algebra & Geometry Seminar
Monday, March 17, 2025
Time: 4:30 p.m. Place: Jeffery Hall, Room 116
Speaker: Maya Banks (University of Illinois Chicago)
Title: Minimal Degree Curves and Scrolls in Weighted Projective Space
Abstract: A nondegenerate variety in projective space satisfies the condition that its degree is bounded below by 1 more than its codimension. Varieties attaining this lower bound—so-called "varieties of minimal degree"—were classified by Bertini and Del Pezzo and exhibit several nice properties, for instance, they are generated by quadrics and have linear syzygies. This theory of minimal degree varieties may be generalized to study varieties in weighted projective spaces. We will discuss bounds on the degree of a nondegenerate variety in certain weighted projective spaces, as well as curves and 'weighted scrolls' which attain the minimal degree bound, and some of their syzygetic properties.
Date
Friday March 14, 2025Location
Jeffrey Hall, Room 319Math & Stats Department Colloquium
Friday, March 14, 2025
Time: 10:30 p.m. Place: Jeffery Hall, Room 319
Speaker: Giuseppe Maria Coclite (Politecnico di Bari)
Title: Vanishing viscosity versus Rosenau approximation for scalar conservation laws: the fractional case
Abstract: In this talk, we consider approximations of scalar conservation laws by adding nonlocal diffusive operators. In particular, we consider solutions associated with fractional Laplacian and fractional Rosenau perturbations and show that, for any $t>0$, the mutual $L^1$ distance of their profiles is negligible as compared to their common distance to the underlying inviscid entropy solution.We provide explicit examples showing that our rates are optimal in the supercritical and critical cases, in one space dimension and for strictly convex fluxes. For subcritical equations, our rates are not optimal but they remain explicit. Those results were obtained in collaboration with N. Alibaud, M. Dalery, and C. Donadello.
Date
Friday March 21, 2025Location
319 JEFFERY HALLFriday, March 21, 2025
Time: 10:30 a.m. Place: Jeffery Hall, Room 319
Speaker: Fabian Bleitner (McMaster University)
Title: Buoyancy-Driven Flows With Navier-Slip Boundary Conditions
Abstract: In this talk two-dimensional buoyancy-driven flows are investigated. While usually the Navier-Stokes equations are equipped with no-slip boundary conditions, here we focus on the Navier-slip conditions that, depending on the system at hand, better reflect the physical behavior. In particular, we study two systems, Rayleigh-Bénard convection and a closely related problem without thermal diffusion. In the former, bounds on the vertical heat transfer, given by the Nusselt number, with respect to the strength of the buoyancy force, characterized by the Rayleigh number, are derived. These bounds hold for a broad range of applications, allowing for non-flat boundaries, any sufficiently smooth positive slip coefficient, and are valid over all ranges of the Prandtl number, a system parameter determined by the fluid. For the thermally non-diffusive system, regularity estimates are proven. Up to a certain order, these bounds hold uniformly in time, which, combined with estimates for their growth, provide insight into the long-time behavior. In particular, solutions converge to the hydrostatic equilibrium, where the fluid's velocity vanishes and the buoyancy force is balanced by the pressure gradient.
The Faculty of Mathematics and Statistics will be holding an information session for First-Year students regarding the New Modular Degree Plans. You'll be able to learn more about what has changed and the choices you have as a currently registered student. Join us on Tuesday, March 11 from 5:30 pm - 6:30 pm in Jeffery Hall - Room 127.
In 2022, the Kingston, Frontenac, Lennox & Addington Public Health (KFL&A PH) region saw a sharp increase in syphilis cases. Local infection rates had more than doubled the provincial average, and reports of congenital syphilis, where the infection is passed from parent to baby, were on the rise.
