Events for 04/26/2019 from all calendars

Working Seminar on Quantum Computation and Quantum Information

Time: 10:30AM - 12:00PM

Location: BLOC 624

Speaker: Michael Brannan, TAMU

Title: Rigid C*-tensor categories, VI

Algebra and Combinatorics Seminar

Time: 3:00PM - 4:00PM

Location: BLOC 628

Speaker: Yue Cai, Texas A&M University

Title: Rational parking functions

Abstract: Vector parking functions are sequences of non-negative integers whose order statistics are bounded by a given integer sequence $(a_0, a_1, \dots, a_n)$. In this talk, we will generalize the notion to parking functions with a linear boundary of rational slope. Using the theory of fractional power series and the Newton-Puiseux Theorem, we convert an Appell relation of Goncarov polynomials to the exponential generating function for rational parking functions in terms of elementary symmetric functions. Time permits, we will also discuss the case of vector parking functions with periodic boundaries. This is joint work with Catherine Yan.

Student Working Seminar in Groups and Dynamics

Time: 3:00PM - 4:00PM

Location: BLOC 506A

Speaker: Konrad Wrobel

Title: Mixing Properties and Comeager Subsets of Act(G,X,\mu)

Abstract: One of the early results in measurable dynamics, due to Halmos, is the fact that ergodic transformations form a comeager subset of the set of Aut(X,\mu). I will discuss several similar results when the group acting is not $\mathbb{Z}$. In particular, I will be concerned with groups that have property (T) or the Haagerup Approximation Property.

Geometry Seminar

Time: 4:00PM - 5:00PM

Location: BLOC 628

Speaker: Michael Di Pasquale, Colorado State University

Title: The asymptotic containment problem for symbolic powers of ideals

Abstract: The symbolic powers of an ideal I, denoted I^(s), are an important geometric analogue of taking regular powers. There is significant interest in the containment problem; that is studying which pairs (r,s) satisfy that I^(s) is contained in I^r. A celebrated result of Ein,Lazarsfeld, and Smith and Hochster and Huneke states that I^(hr) is contained in I^r where I is an ideal of big height h in a regular ring. In an effort to quantify these containment results more precisely, the notions of resurgence and asymptotic resurgence of an ideal were introduced by Bocci and Harbourne and Guardo, Harbourne, and Van Tuyl. We show that the asymptotic resurgence of an ideal can be computed using integral closures, which leads to a characterization of asymptotic resurgence as the maximum of finitely many Waldschmidt-like constants. For monomial ideals these constants can be computed by solving linear programs over the symbolic polyhedron introduced by Cooper, Embree, Ha, and Hoefel. This makes it reasonable to compute the asymptotic resurgence of many monomial ideals, leading to some interesting examples related to combinatorial optimization where asymptotic resurgence and resurgence are different. This is joint work with Chris Francisco, Jeff Mermin, and Jay Schweig.