BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Stefaan Vaes (KU Leuven) DTSTART:20220211T163000Z DTEND:20220211T173000Z DTSTAMP:20260404T111216Z UID:ReginaPIMS/1 DESCRIPTION:Title: Classification questions in operator algebras and ergodic theory \nby Stefaan Vaes (KU Leuven) as part of University of Regina pims dis tinguished lectures\n\n\nAbstract\nThe theme of this lecture is the dichot omy between amenability and non-amenability\, both in operator algebras an d ergodic theory. I will review the fundamental classification results for amenable von Neumann algebras due to Connes and Haagerup. Then I will foc us on the nonamenable case\, where Popa's deformation/rigidity theory has led to striking rigidity theorems for von Neumann algebras associated with groups and actions of groups on measure spaces. I will survey some recent results\, including the computation of invariants of II$_1$ factors and t he challenging problem of deciding when II$_1$ factors can be embedded one into the other.\n\nFollow the link to register in advance.\n LOCATION:https://stable.researchseminars.org/talk/ReginaPIMS/1/ END:VEVENT BEGIN:VEVENT SUMMARY:Tatjana Miljkovic (Miami University) DTSTART:20221014T213000Z DTEND:20221014T223000Z DTSTAMP:20260404T111216Z UID:ReginaPIMS/2 DESCRIPTION:Title: An overview of the recent loss modeling approaches and their imp act on risk measures\nby Tatjana Miljkovic (Miami University) as part of University of Regina pims distinguished lectures\n\n\nAbstract\nThe “ key risk measures” such as Value-at-Risk (VaR) and Conditional Tail Expe ctation (CTE) are important for capital allocation decisions as they infor m actuaries and risk managers about the degree to which a line of business or a company is exposed to a particular aspect of risk. These measures ar e typically estimated based on the best-fitting statistical model selected from a set of models considered in loss modeling.\n\nIn this talk\, three different approaches for finding the best fitting model will be introduce d using computational tools. The first approach is based on finite mixture s where the components belong to the same parametric distribution family. The second approach uses composite models where two different distribution s are used for the head and tail and these distributions are combined in a smooth way at a specific threshold. Finally\, the model averaging approac h will be introduced and applied to the estimation of risk measures. The r esults of the simulation studies will be discussed as well as the applicat ions using two popular data sets on Danish Fire and Norwegian Fire losses. \n\nPlease register in advance to receive the Zoom link.\n LOCATION:https://stable.researchseminars.org/talk/ReginaPIMS/2/ END:VEVENT BEGIN:VEVENT SUMMARY:Alexander Kupers (University of Toronto) DTSTART:20221028T213000Z DTEND:20221028T223000Z DTSTAMP:20260404T111216Z UID:ReginaPIMS/3 DESCRIPTION:Title: Diffeomorphisms of discs\nby Alexander Kupers (University of Toronto) as part of University of Regina pims distinguished lectures\n\nL ecture held in RIC 208.\n\nAbstract\nDiscs are among the simplest manifold s\, but their groups of diffeomorphisms can be very complicated. I will de scribe the techniques from geometry topology and dynamics that were used t o understand these groups in low dimensions\, the relationship of these gr oups to stable homotopy theory and number theory in high dimensions\, and recent breakthroughs in understanding their rational homotopy type. This t alk will be aimed at a broad audience.\n\nThe talk will be held in person and livestreamed on Zoom. Register in advance to receive the Zoom link.\n LOCATION:https://stable.researchseminars.org/talk/ReginaPIMS/3/ END:VEVENT BEGIN:VEVENT SUMMARY:Emily Riehl (Johns Hopkins University) DTSTART:20230210T213000Z DTEND:20230210T223000Z DTSTAMP:20260404T111216Z UID:ReginaPIMS/4 DESCRIPTION:Title: A reintroduction to proofs\nby Emily Riehl (Johns Hopkins Un iversity) as part of University of Regina pims distinguished lectures\n\n\ nAbstract\nIn an introduction to proofs course\, students learn to write p roofs informally in the language of set theory and classical logic. In thi s talk\, I'll explore the alternate possibility of teaching students to wr ite proofs informally in the language of dependent type theory. I'll argue that the intuitions suggested by this formal system are closer to the int uitions mathematicians have about their praxis. Furthermore\, dependent ty pe theory is the formal system used by many computer proof assistants both "under the hood" to verify the correctness of proofs and in the vernacula r language with which they interact with the user. Thus\, students could p ractice writing proofs in this formal system by interacting with computer proof assistants such as Coq and Lean.\n\nRegister in advance to receive t he Zoom link.\n LOCATION:https://stable.researchseminars.org/talk/ReginaPIMS/4/ END:VEVENT BEGIN:VEVENT SUMMARY:Jiguo Cao (Simon Fraser University) DTSTART:20230915T213000Z DTEND:20230915T223000Z DTSTAMP:20260404T111216Z UID:ReginaPIMS/5 DESCRIPTION:Title: Machine Learning for Functional Data\nby Jiguo Cao (Simon Fr aser University) as part of University of Regina pims distinguished lectur es\n\n\nAbstract\nFunctional data analysis (FDA) is a growing statistical field for analyzing curves\, images\, or any multidimensional functions\, in which each random function is treated as a sample element. Functional d ata is found commonly in many applications such as longitudinal studies an d brain imaging. In this talk\, I will present a methodology for integrati ng functional data into deep neural networks. The model is defined for sca lar responses with multiple functional and scalar covariates. A by-product of the method is a set of dynamic functional weights that can be visualiz ed during the optimization process. This visualization leads to greater in terpretability of the relationship between the covariates and the response relative to conventional neural networks. The model is shown to perform w ell in a number of contexts including prediction of new data and recovery of the true underlying relationship between the functional covariate and s calar response\; these results were confirmed through real data applicatio ns and simulation studies.\n\nPlease register in advance at the provided l ink.\n LOCATION:https://stable.researchseminars.org/talk/ReginaPIMS/5/ END:VEVENT BEGIN:VEVENT SUMMARY:Jacob Tsimerman (University of Toronto) DTSTART:20230922T213000Z DTEND:20230922T223000Z DTSTAMP:20260404T111216Z UID:ReginaPIMS/6 DESCRIPTION:Title: Transcendence of period integrals over function fields\nby J acob Tsimerman (University of Toronto) as part of University of Regina pim s distinguished lectures\n\n\nAbstract\nPeriods are integrals of different ial forms\, and their study spans many branches of mathematics\, including diophantine geometry\, differential algebra\, and algebraic geometry. If one restricts their attention to periods arising over $\\mathbb{Q}$\, then the Grothendieck Period Conjecture is a precise way of saying that these are as transcendental as is allowed by the underlying geometry. While this is a remarkably general statement (and very open)\, it does not include a nother major (also open!) conjecture in transcendence theory - the Schanue l conjecture. In particular\, $e$ is not a period\, even though it can be described through periods via the relation that the integral from 1 to $e$ of $dx/x$ is 1. We shall present a generalization due to André which uni fies the two conjectures in a satisfactory manner.\n\nIn the (complex) fun ction field case\, a lot more is known. The Grothendieck Period Conjecture has been formulated and proved by Ayoub and Nori. We shall explain the ge ometric analogue of the André - Grothendieck Period Conjecture and presen t its proof. It turns out that this conjecture is (almost) equivalent to a functional-transcendence statement of extreme generality known as the Ax- Schanuel conjecture\, which has been the subject of a lot of study over th e past decade in connection with unlikely intersection problems. The versi on relevant to us is a comparison between the algebraic and flat coordinat es of geometric local systems. We will explain the ideas behind the proofs of this Ax-Schanuel conjecture and explain how it implies the relevant pe riod conjecture.\n\nRegister in advance to receive the Zoom link.\n LOCATION:https://stable.researchseminars.org/talk/ReginaPIMS/6/ END:VEVENT BEGIN:VEVENT SUMMARY:Ben Williams (University of British Columbia) DTSTART:20231020T213000Z DTEND:20231020T223000Z DTSTAMP:20260404T111216Z UID:ReginaPIMS/7 DESCRIPTION:Title: Topology and Azumaya algebras\nby Ben Williams (University o f British Columbia) as part of University of Regina pims distinguished lec tures\n\nLecture held in RIC 209.\n\nAbstract\nAn Azumaya algebra is somet hing that is "locally" isomorphic to a matrix algebra. By varying the sens e of "locally"\, we arrive at different incarnations of the concept. The m otivating example is that of central simple algebras over a field. In this talk\, I will concentrate on the topological aspects of the idea. I will give examples and show that the flexibility of topology allows one to prod uce counterexamples in algebra. At the end\, I will mention some problems I do not know how to solve.\n\nRegister in advance for the Zoom link.\n\nT his event is supported by PIMS.\n LOCATION:https://stable.researchseminars.org/talk/ReginaPIMS/7/ END:VEVENT BEGIN:VEVENT SUMMARY:Teena Gerhardt (Michigan State University) DTSTART:20240308T213000Z DTEND:20240308T223000Z DTSTAMP:20260404T111216Z UID:ReginaPIMS/8 DESCRIPTION:Title: Interactions between topology and algebra: advances in algebraic K-theory\nby Teena Gerhardt (Michigan State University) as part of Un iversity of Regina pims distinguished lectures\n\n\nAbstract\nThe field of algebraic topology has exposed deep connections between topology and alge bra. One example of such a connection comes from algebraic K-theory. Algeb raic K-theory is an invariant of rings\, defined using tools from topology \, that has important applications to algebraic geometry\, number theory\, and geometric topology. Algebraic K-groups are difficult to compute\, but advances in algebraic topology have led to many recent computations which were previously intractable. In this talk I will introduce algebraic K-th eory and its applications\, and discuss recent advances in this field.\n\n Register in advance to receive the Zoom link.\n LOCATION:https://stable.researchseminars.org/talk/ReginaPIMS/8/ END:VEVENT BEGIN:VEVENT SUMMARY:Octav Cornea (Université de Montréal) DTSTART:20250417T203000Z DTEND:20250417T213000Z DTSTAMP:20260404T111216Z UID:ReginaPIMS/9 DESCRIPTION:Title: Complexity of Lagrangian submanifolds\nby Octav Cornea (Univ ersité de Montréal) as part of University of Regina pims distinguished l ectures\n\n\nAbstract\nLagrangian submanifolds are a central object of stu dy in symplectic topology. Their rigidity properties have been uncovered v ia Floer theory since the early ’90’s. The talk will briefly review th e subject\, in particular how triangulated category structures naturally a rise in this context through work of Donaldson\, Kontsevich\, Fukaya\, and others. Further\, will be discussed the more recent\, natural role of per sistence theory\, in the sense common in data science. Finally\, we will o utline how complexity measurements based on persistence methods reflect to pological and dynamical invariants\, such as topological entropy.\n\nRegis ter in advance to receive the Zoom link.\n\nThis event is supported by PIM S.\n LOCATION:https://stable.researchseminars.org/talk/ReginaPIMS/9/ END:VEVENT END:VCALENDAR