Infosheet (March 21st, 2017) |
Queen's University - Department of Mathematics and Statistics |
Tuesday, March 21 |
Dynamics Seminar Time: 3.30 p.m. Place: Jeffery 422 |
Speaker: Francesco Cellarosi, Queen’s University Title: The Impossible Pointwise Ergodic Theorem in Infinite Ergodic Theory Abstract Attached |
Wednesday, March 22 |
Curves Seminar Time: 3:30 pm. Place: Jeffery 422 |
Speaker: Mike Roth Title: G-linearizations of line bundles II Abstract Attached |
Thursday, March 23 |
Math Club Time: 5:30 p.m. Place: Jeffery 118 |
Speaker: Jamie Mingo Title: The Lemniscate and Generalized Trigonometric Functions Abstract Attached |
Friday, March 24 |
Number Theory Seminar Time: 10:30 a.m. Place: Jeffery 422 |
Speaker: Mike Roth Title: A Liouville approximation theorem for varieties and an application to cubic surfaces Abstract Attached |
Friday, March 24 |
Department Colloquium Time: 2:30 p.m. Place: Jeffery 234 |
Speaker: Ioana Dumitriu, University of Washington, Seattle Title: Spectra of random regular and quasi-regular graphs Abstract Attached |
Monday, March 27 |
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, Part II 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 21, 3:30 p.m. Jeffery 422 - Dynamics Seminar
Speaker: Francesco Cellarosi
Title: The Impossible Pointwise Ergodic Theorem in Infinite Ergodic Theory
Abstract: I will discuss a classical theorem by Aaronson, which states that in the case of a conservative ergodic transformation on a sigma-finite infinite measure space, there is no normalizing sequence for the ergodic sums yielding almost everywhere convergence, unlike the classical pointwise ergodic theorem by Birkhoff.
Wednesday, March 22, 3:30 p.m. Jeffery 422 - Curves Seminar
Speaker: Mike Roth
Title: G-linearizations of line bundles II
Abstract: We will prove the exactness of the basic sequence relating Pic^G(X) and Pic(X), and discuss related topics.
Thursday, March 23, 5:30 p.m. Jeffery 118 - Math Club
Speaker: Jamie Mingo
Title: The Lemniscate and Generalized Trigonometric Functions
Abstract: Since ancient times there have been two ways of measuring an angle: the rise over the run, or as a fraction of a circle. We use the trigonometric functions to convert a measurement in one system to the other. The usual sine and cosine functions are often called the circular functions. A similar construction can be applied to a hyperbola resulting in the hyperbolic sine and cosine functions. In the 18th century Fagnano and Euler worked out the corresponding functions for the lemniscate.
We will discuss the basic properties of the lemniscate functions and indicate some of their connections to current research.
Friday, March 24, 10:30 a.m. Jeffery 422 - Number Theory Seminar
Speaker: Mike Roth
Title: A Liouville approximation theorem for varieties and an application to cubic surfaces
Abstract: Diophantine approximation studies the problem of approximating an algebraic point by rational ones. Results in Diophantine approximation are used to deduce Diophantine results from geometric conditions.
The first results on Diophantine approximation were by Dirichlet and
Liouville, and concern approximation on the real line. Liouville’s result
was later greatly improved by Klaus Roth. In general Roth’s theorem is much
better than Liouville’s theorem, the exception being when the point being
approximated is itself rational.
This talk will give an extension of Liouville’s theorem to algebraic
varieties, and an application to cubic surfaces.
Friday, March 24, 2:30 p.m. Jeffery 234 - Department Colloquium
Speaker: Ioana Dumitriu
Title: Spectra of random regular and quasi-regular graphs
Abstract: The spectra of random graphs and networks have been widely studied in the last two decades, both in theoretical contexts (relating to random matrices and universality) and practical ones (with applications to mixing, sampling, community detection). From a random matrix perspective, the "natural" random graphs have independent edges (Erdos-Renyi and Chung-Lu-Vu models, with or without block structure); however, regular graphs have also been shown to share many of the spectral properties of the independent-edge ones. Recently, some of these studies have been extended to quasi-regular random graphs. We will survey some of these results and potential applications to community detection.
Monday, March 27, 2:30 p.m. Jeffery 202
Seminar in Free Probability and Random Matrices
Speaker: Yinzheng Gu
Title: Analytic subordination for bi-free convolution, Part II
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.
Seminar website: http://www.mast.queensu.ca/~mingo/seminar/