Infosheet (March 14th, 2017)

Queen's University - Department of Mathematics and Statistics


Tuesday, March 14

Dynamics Seminar

Time: 3.30 p.m.

Place: Jeffery 422

Speaker: Bahman Gharesifard

Title: Invariance Principle for Set-valued Dynamical Systems and an Application

Abstract Attached

Wednesday, March 15

Curves Seminar

Time: 3:30 pm.

Place: Jeffery 422

Speaker: Mike Roth

Title: G-linearizations of line bundles

Abstract Attached

Thursday, March 16

Math Club

Time: 5:30 p.m.

Place: Jeffery 118

Speaker: Andrew McEachern

Title: The 25 billion dollar eigenvalue

Abstract Attached

Friday, March 17

Number Theory Seminar

Time: 10:30 a.m.

Place: Jeffery 422

Speaker: Francesco Cellarosi

Title: On the Riemann zeta function and Brownian excursions

Abstract Attached

Friday, March 17

Department Colloquium

Time: 2:30 p.m.

Place: Jeffery 234

Speaker: Jordan Watts, University of Colorado, Boulder

Title: Quotients of Lie Group Actions

Abstract Attached

Monday, March 20

Seminar in Free Probability

Time: 2:30 p.m.

Place: Jeffery 202

Speaker: Yinzheng Gu, Queen’s University

Title: Analytic subordination for bi-free convolution

Abstract Attached

Items for the Info Sheet should reach Anne ( burnsa@queensu.ca) by noon on Monday. The Info Sheet is published every Tuesday.


CALCULATOR EXAM POLICY , the official calculator is a Casio fx-991, or one with a blue sticker as issued by School of Business. All exam cover pages must only refer to these calculators only; any other exam cover, including other calculators (ie gold sticker) will not be accepted by the exams office. Proctors are going to be instructed to be less lenient with calculators that aren’t Casio fx-991 (or blue sticker from COMM), and will likely to be taking them away.


Tuesday, March 14, 3:30 p.m. Jeffery 422 - Dynamics Seminar

Speaker: Bahman Gharesifard

Title: Invariance Principle for Set-valued Dynamical Systems and an Application

Abstract: Invariance Principles for Set-valued Dynamical Systems and an Application Abstract: We state and prove an invariance principle for studying the stability of set-valued discrete-time dynamical systems, and discuss an application of this result for designing algorithms for balancing directed graphs, with only local information about their graph topology.


Wednesday, March 15, 3:30 p.m. Jeffery 422 - Curves Seminar

Speaker: Mike Roth

Title: G-linearizations of line bundles

Abstract: We will study when a line bundle on a projective variety admits a G-linearization.


Thursday, March 16, 5:30 p.m. Jeffery 118 - Math Club

Speaker: Andrew McEachern

Title: The 25 billion dollar eigenvalue

Abstract: Google's success derives in large part from its PageRank algorithm, which ranks the importance of web pages via search key words according to an eigenvector of a weighted matrix.

This talk will be an exposition of the PageRank algorithm, which uses standard linear algebra techniques and theorems you would see in any undergraduate classroom, such as the column stochasticity and a special case of the Perron-Frobenius Theorem.


Friday, March 17, 10:30 a.m. Jeffery 422 - Number Theory Seminar

Speaker: Francesco Cellarosi

Title: On the Riemann zeta function and Brownian excursions

Abstract: Following a 2001 paper by P. Biane, J. Pitman and M. Yor, I will review some results connecting the Riemann zeta function and the Jacobi theta function to some probability laws governing sums of independent exponential random variables. These laws are related to the 1-dimensional Brownian motion and higher dimensional Bessel processes.


Friday, March 17, 2:30 p.m. Jeffery 234 - Department Colloquium

Speaker: Jordan Watts

Title: Quotients of Lie Group Actions

Abstract: It is well-known that the orbit space of a compact Lie group action is a (local) semi-algebraic variety. The algebraic structure of this variety is obtained locally via invariant theory, and by a famous result of Schwarz we also obtain a differentiable structure on this space, and so we can do analysis on it as well. In fact, the differentiable structure determines the variety. There is a question of uniqueness: given a differentiable semi-algebraic variety that comes from a compact Lie group action, is there a unique compact Lie group action, up to some form of equivalence, that yields the variety? In general, the answer is "no". However, if we restrict our attention to group actions whose stabilizers are all finite (that is, orbifolds), then the answer is yes. We will talk about this result, as well as applications of it to circle actions; especially symplectic circle actions. In particular, symplectic quotients by such circle actions are never orbit spaces of Lie group actions unless they are orbifolds, with restrictions on when this can happen. This extends a result of Herbig-Schwarz-Seaton, which is concerned with orbifolds in a slightly more algebraic setting. This talk is designed for a general mathematical audience; no prior knowledge of symplectic or algebraic geometry, invariant theory, etc., is required.


Monday, March 20, 2:30 p.m. Jeffery 202

Seminar in Free Probability and Random Matrices

Speaker: Yinzheng Gu

Title: Analytic subordination for bi-free convolution

Abstract: We discuss some analytic properties of the additive bi-free convolution, both scalar-valued and operator-valued. We show that using the one-variable subordination functions associated with the additive free convolution, simple formulas for additive bi-free convolutions can be derived. As an application, we prove a result about atoms of the additive bi-free convolution.

Contact Info

Department of Math & Stats
Jeffery Hall, 48 University Ave.
Kingston, ON Canada, K7L 3N6
Phone: (613) 533-2390
Fax: (613) 533-2964
mathstat@mast.queensu.ca
Office Hours: 8:30am-12:00pm & 1:00pm-4:30pm

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