Infosheet (January 24th, 2017) |
Queen's University - Department of Mathematics and Statistics |
Tuesday, January 24 |
Seminar in Free Probability and Random Matrices Time: 2:30 p.m. Place: Jeffery 222 |
Speaker: Jamie Mingo, Queen’s University Title: Free Probability of Type B, Part II Abstract Attached |
Tuesday, January 24 |
Dynamics Seminar Time: 3:30 p.m. Place: Jeffery 422 |
Speaker: Andrey Gogolev, Binghamton University Title: Classification in hyperbolic dynamics Abstract Attached |
Wednesday, January 25 |
Curves Seminar Time: 3:30 p.m. Place: Jeffery 422 |
Speaker: Mike Roth Title: Quotients of affine varieties by reductive groups II Abstract Attached |
Thursday, January 26 |
Math Club
Time: 5:30 p.m. Place: Jeffery 118 |
Speaker: Mike Roth Title: Permuations given by polynomials Abstract Attached |
Friday, January 27 |
Number Theory Seminar Time: 10:30 a.m. Place: Jeffery 422 |
Speaker: Vaidehee Thatte, Queen’s University Title: Some examples of Artin-Schreier Extensions of Valuation Fields (“No Theory – II”) Abstract Attached |
Friday, January 27 |
Department Colloquium Time: 3:30 p.m. Place: Jeffery 234 |
Speaker: Todd Parsons, Université Pierre et Marie Curie Title: The stochastic evolution of pathogen virulence Abstract Attached |
Items for the Info Sheet should reach Anne ( burnsa@queensu.ca) by noon on Monday. The Info Sheet is published every Tuesday.
Tuesday, January 24, 2:30 p.m. Jeffery 222
Seminar in Free Probability and Random Matrices
Speaker: Jamie Mingo
Title: Free Probability of Type B, Part II
Abstract: Since Voiculescu introduced free independence 35 years ago, many variants have appeared: Boolean, monotone, type B, second order, higher order, real, quaternionic, infinitesimal, and bi-free independence (plus combinations of the above) to name a few. Most of the constructions are given combinatorially, but some have an interpretation in terms of analytic functions. I will discuss the 2003 paper of Biane, Goodman, and Nica, which introduced freeness of type B.
This will be the first of two lectures. This lecture will describe free cumulants of type B and type B freeness. The second lecture will explain how the hyperoctahedral group comes into play and hence why this is called type B freeness.
Seminar website: http://www.mast.queensu.ca/~mingo/seminar/
Tuesday, January 24, 3:30 p.m. Jeffery 422 - Dynamics Seminar
Speaker: Andrey Gogolev
Title: Classification in hyperbolic dynamics
Abstract:
Impossibility to predict the future based on current (no matter how
precise) observation of a dynamical system is known as deterministic chaos.
Hyperbolicity is the geometric mechanism behind deterministic chaos and is
observed in many real-life dynamical systems such as double pendulum and
atmospheric convection.
We will overview the status of the classification problem of uniformly hyperbolic diffeomorphisms, which are ideal models for hyperbolicity. Then we will focus on a more general class of partially
hyperbolic diffeomorphisms. Partial hyperbolicity plays an important role in smooth dynamics due to its
ties to stable ergodicity and robust transitivity. We will discuss recent progress on classification questions in partially hyperbolic dynamics.
Wednesday, January 25, 3:30 p.m. Jeffery 422 - Curves Seminar
Speaker: Mike Roth
Title: Quotients of affine varieties by reductive groups II
Abstract: We will prove the basic results about the quotient of an affine variety by the action of a reductive group.
Thursday, January 26, 5:30 p.m. Jeffery 118 - Math Club
Speaker: Mike Roth
Title: Permuations given by polynomials
Abstract: How can the graphs of polynomials of one variable cross each other over x=0? You might suspect that any pattern is possible, and this is true as long as there are at most three polynomials. Rather surprisingly it is not true when there are four or more, a fact about polynomials only discovered in 2009. This talk will explain the problem, the answer, and some connections with other parts of mathematics.
Friday, January 27, 10:30 a.m. Jeffery 422 - Number Theory Seminar
Speaker: Vaidehee Thatte
Title: Some examples of Artin-Schreier Extensions of Valuation Fields (“No Theory – II”)
Abstract: We will discuss a few examples of Artin-Schreier extensions of valuation fields K of prime characteristic p and explicitly compute some invariants of ramification theory in each case. This is a continuation of the first "No Theory" talk.
Note/Recall: In the last talk, we discussed the basic structure of such extensions and properties of valuations involved.
Friday, January 27, 3:30 p.m. Jeffery 234 - Department Colloquium
Speaker: Todd Parsons
Title: The stochastic evolution of pathogen virulence
Abstract: Life history theory provides a powerful framework to understand the evolution of pathogens in both epidemic and endemic situations. This framework, however, relies on the assumption that
pathogen populations are very large and that one can neglect the effects of demographic stochasticity. I will explore the effects of finite population size on the evolution of pathogen virulence and transmission. I will show that demographic stochasticity introduces additional evolutionary forces that can qualitatively affect the dynamics and the evolutionary outcome, and discuss the importance of the shape of pathogen fitness landscape and host heterogeneity on the balance between mutation, selection and genetic drift. In particular, I will discuss scenarios where finite population size can either select for lower or higher virulence.
This is joint work with Troy Day, Sylvain Gandon and Amaury Lambert.