Infosheet (January 23rd, 2018) |
Queen's University - Department of Mathematics and Statistics |
Tuesday, January 23 |
MSC Project Presentation Time: 10:00 a.m. Place: Jeffery 521 |
MSC Student: Stergios Gianniotis Thesis Title: Empirical Study on Bayesian and Frequentist Model Calibration of Computer Models Supervisor: D. Lin |
Tuesday, January 23 |
Seminar in Free Probability and Random Matrices Time: 4:00 p.m. Place: Jeffery 319 |
Speaker: Rob Martin, University of Cape Town Title: A multi-variable de Branges-Rovnyak model for row contractions Abstract Attached |
Wednesday, January 24 |
Number Theory Seminar Time: 2:15 p.m. Place: Jeffery 319 |
Speaker: François Séguin Title: Heights of elliptic curves and the elliptic analogue of the two-variable Artin conjecture Abstract Attached |
Wednesday, January 24 |
Curves Seminar Time: 3:30 p.m. Place: Jeffery 319 |
Speaker: Mike Roth Title: Zak’s theorems on tangencies I Abstract Attached |
Thursday, January 25 |
Math Club Time: 5:30 p.m. Place: Jeffery 118 |
Speaker: M. Ram Murty Title: Stirling’s Formula Abstract Attached |
Friday, January 26 |
MSC Thesis Defense Time: 10:00 a.m. Place: Jeffery 521 |
MSC Student: Jingyi Liang Thesis Title: Modelling of Dynamic computer Experiments with Both Qualitative and Quantitative Variables Supervisors: D. Lin and G. Takahara |
Friday, January 26 |
Dynamics Seminar Time: 10:30 a.m. Place: Jeffery 422 |
Speaker: Jory Griffin, Queen’s University Title: Limit Theorems for Skew Translations Abstract Attached |
Friday, January 26 |
Grad Seminar Time: 11:30 a.m. Place: Jeffery 118 |
Speaker: Cédric Villani Title: The Extraordinary Theorems of John Nash (The Royal Institution, Nov 2016) Abstract Attached |
Friday, January 26 |
Department Colloquium Time: 2:30 p.m. Place: Jeffery 234 |
Speaker: Milian Derpich, Universidad Técnica Federico Santa Maria, Valparaiso, Chile Title: The Differential Entropy Gain Created by Linear Time-Invariant Systems Abstract Attached |
Items for the Info Sheet should reach Anne ( burnsa@queensu.ca) by noon on Monday. The Info Sheet is published every Tuesday.
Seminar in Free Probability and Random Matrices
Tuesday, January 23, 4:00 p.m. Jeffery 319
Speaker: Rob Martin
Title: A multi-variable de Branges-Rovnyak model for row contractions
Abstract: In the operator-model theory of de Branges and Rovnyak, any completely non-coisometric (CNC) contraction on Hilbert space is represented as the adjoint of the restriction of the backward shift
to a de Branges-Rovnyak subspace of the classical (vector-valued) Hardy space of analytic functions in the open unit dis.
We provide a natural extension of this model to the setting of CNC (row) contractions from several copies of a Hilbert space into itself. A canonical extension of Hardy space to several complex dimensions is the Drury-Arveson space, and the appropriate analogue of the adjoint of the restriction of the backward shift to a de Branges-Rovnyak space is a Gleason solution, a row contraction whose adjoint acts as a several-variable difference quotient. Our several-variable model completely characterizes the class of all CNC row contractions which can be represented as (extremal contractive) Gleason solutions for a multi-variable de Branges-Rovnyak subspace of (vector-valued) Drury-Arveson space.
Seminar website: http://www.mast.queensu.ca/~mingo/seminar/
Wednesday, January 24, 2:15 p.m. Jeffery 319 - Number Theory Seminar
Speaker: François Séguin
Title: Heights of elliptic curves and the elliptic analogue of the two-variable Artin conjecture
Abstract: Similar to the way Lang and Trotter adapted Artin's primitive root conjecture in the case of elliptic curves, we consider this natural adaptation for the two-variable Artin Conjecture. In light of our recent results for the two-variable setting, we present similar, unconditional lower bounds for this elliptic analogue.
Wednesday, January 24, 3:30 p.m. Jeffery 319 - Curves Seminar
Speaker: Mike Roth
Title: Zak’s theorems on tangencies I
Abstract: We will prove some results due to F. Zak on the linear spaces tangent to a smooth variety, the Gauss map of an embedded variety, and a related questions.
Thursday, January 25, 5:30 p.m. Jeffery 118 - Math Club
Speaker: M. Ram Murty
Title: Stirling’s Formula
Abstract: In 1733, Stirling found an asymptotic approximation to n! which playes a fundamental role in probability theory. He proved that n!∼(n/e)n2πn‾‾‾‾√ as n tends to infinity. We will give a "first-year calculus'' proof of this and also highlight a few of its applications.
Friday, January 26, 10:30 a.m. Jeffery 422 - Dynamics Seminar
Speaker: Jory Griffin
Title: Limit Theorems for Skew Translations
Abstract: Bufetov, Bufetov-Forni and Bufetov-Solomyak have proved limit theorems for translation flows, horocycle flows and tiling flows, respectively. We present here analogous results for skew translations of a torus.
Friday, January 26, 11:30 a.m. Jeffery 118 - Grad Seminar
Speaker: Cédric Villani
Title: The Extraordinary Theorems of John Nash (The Royal Institution, Nov 2016)
Abstract: Fields medal winner Cédric Villani takes us through the very special world of mathematical creation of John Nash, who founded several new chapters of game theory and geometric analysis in just a few revolutionary contributions that seemed to come from nowhere.
Friday, January 26, 2:30 p.m. Jeffery 234 - Department Colloquium
Speaker: Milan Derpich
Title: The Differential Entropy Gain Created by Linear Time-Invariant Systems
Abstract: The differential entropy of a continuous-valued random variable quantifies the uncertainty associated with the latter, and plays a crucial role in many fundamental result of Information Theory. This talk will discuss how the differential entropy rate of a random process exciting a discrete-time linear time invariant (LTI) system relates to that of the random process coming out of it. First, an apparent contradiction between existing results characterizing the difference between these two differential entropy rates, referred to a "differential entropy gain", will be exposed. It will then be shown how and when these results can be reconciled, presenting a geometric interpretation as well as novel results which quantify the differential entropy gain introduced by LTI systems. Finally, some of the implications of these results will be illustrated for three different problems, namely: the rate-distortion function for non stationary processes, an inequality in networked control systems, and the capacity of stationary Gaussian channels.