The Applied Algebra Seminar

A
Monday afternoon research seminar

The seminar is currently organized by Laura Colmenarejo and Nantel Bergeron.

During 2016-17, the seminar takes place from 3:00-4:00 in Ross Building room N638. If you come by bus, the route 196A, 196B takes you to campus from Downsview subway station. If you come by car, you can find the available parking lots here.

The seminar has been running since 1997. The topics of talks have typically been any mixture of algebra with any other field: combinatorics, geometry, topology, physics, etc. Further down this page you will find links to the seminar webpages for previous years. The audience usually consists of 6–12 people, including several graduate students and post-docs. For this reason, speakers are encouraged to devote a portion of their talk to the suggestion of open problems and the directions for research in their area. If you are interested in speaking at the seminar, contact Laura Colmenarejo or Nantel Bergeron.You may also be interested in the Algebraic Combinatorics Seminar at the Fields Institute.

Dates are listed in reverse-chronological order. Unless otherwise indicated, all talks will take place on Monday from 14:30-15:30 in N638 Ross Building (York University).

Date Speaker Title (click titles for abstract) 3 Oct. 2016 Georg Merz

(Math. Institut)26 Sep. 2016 John Maxwell Campbell

(York U.)The evaluation of immaculate functions in terms of the ribbon basis There is an elegant combinatorial formula for evaluating elements of the ribbon basis of NSym in terms of immaculate functions, but there is no known cancellation-free formula for expanding elements of the immaculate basis in terms of ribbon functions in NSym. However, recent research suggests that many different classes of immaculate functions may be evaluated in terms of ribbon functions using cancellation-free Jacobi-Trudi-like formulas. In this talk, we offer a sketch of a proof of a surprising Jacobi-Trudi-like formula for expanding immaculate-rectangles as linear combinations of ribbon functions.12 Sep. 2016 Jake Levinson

(U. of Mich.)(Real) Schubert Calculus from Marked Points on P^1 I will describe a family of Schubert problems on the Grassmannian, defined using tangent flags to points of P^1 (or more generally, a stable curve) in its Veronese embedding. For Schubert problems having a finite set of solutions, the Shapiro-Shapiro Conjecture (later proven by Mukhin-Tarasov-Varchenko) proposed that, when the marked points are all real, the solutions would be as real as possible. More recently, Speyer gave a remarkable description of the real topology of the family in terms of Young tableaux and Schützenberger's jeu de taquin. I will go through this story, then give analogous results on the topology of one-dimensional Schubert problems (where the family consists of curves). In this case the combinatorics involves orbits of so-called "evacuation-shuffling", an algorithm related to tableau promotion and evacuation.

Below you will find links to the seminar webpages for previous years.