LSU Virtual Topology Seminar
Fall 2018–Spring 2019

Organizers: Shea Vela-Vick, Mike Wong
Last updated: Oct 1, 2018

Previous year: Fall 2017–Spring 2018

Time and venueThe LSU Virtual Topology Seminar meets in 233 Lockett Hall, at 3:30 pm CT on Wednesdays.

BroadcastingResearchers from other institutions are welcome to participate in the virtual seminar, which is broadcast online using Viewme, a video collaboration program. If you are interested in joining us, please send an e-mail to cmmwong [at] lsu [dot] edu.

Mailing list If you would like to (un)subscribe to the mailing list, please send an e-mail to shea [at] math [dot] lsu [dot] edu.

Schedule The schedule is updated throughout the academic year, and only confirmed speakers are listed below.
Date Speaker Institution Title
Aug 29, 2018 Ignat Soroko Louisiana State University Dehn functions of subgroups of right-angled Artin groups
Sep 5, 2018 Andrew Zimmer Louisiana State University Limit sets of discrete subgroups
Sep 26, 2018 Yilong Wang Louisiana State University Modular tensor categories and Reshetikhin–Turaev TQFTs I
Oct 10, 2018 Yilong Wang Louisiana State University Modular tensor categories and Reshetikhin–Turaev TQFTs II
Oct 17, 2018 Joshua Sabloff Haverford College Length and width of Lagrangian cobordisms
Oct 24, 2018 Scott Baldridge Louisiana State University TBA
Oct 31, 2018 Matthew Haulmark Vanderbilt University TBA
Jan 9, 2019 Genevieve Walsh Tufts University TBA
Jan 30, 2019 Francesco Lin Princeton University TBA
Mar 27, 2019 Tye Lidman North Carolina State University TBA

Abstracts


Date Aug 29, 2018

Speaker Ignat Soroko

Title Dehn functions of subgroups of right-angled Artin groups

Abstract The question of what is a possible range for the Dehn functions (a.k.a. isoperimetric profile) for certain classes of groups is a natural and interesting one. Due to works of many authors starting with Gromov, we know a lot about the isoperimetric profile for the class of all finitely presented groups. Much less is known for many natural subclasses of groups, such as subgroups of right-angled Artin groups. We prove that polynomials of arbitrary degree are realizable as Dehn functions of subgroups of right-angled Artin groups. The key step is to construct for each natural k a free-by-cyclic group with the monodromy automorphism growing as n^k, which is virtually special in the sense of Haglund and Wise. Then its double will have Dehn function growing as n^{k+2}. This is a joint work with Noel Brady.

Date Sep 5, 2018

Speaker Andrew Zimmer

Title Limit sets of discrete subgroups

Abstract Given a discrete group of matrices one can define an associated limit set in projective space. In this talk I'll describe some results concerning the regularity of this limit set when the discrete group satisfies certain geometric properties.

Date Sep 26, 2018

Speaker Yilong Wang

Title Modular tensor categories and Reshetikhin–Turaev TQFTs I

Abstract In this talk, we give a detailed introduction to modular tensor categories and the Reshetikhin–Turaev TQFT associated to them. Time permitted, I will talk about algebraic properties of the RT-TQFTs.

Date Oct 10, 2018

Speaker Yilong Wang

Title Modular tensor categories and Reshetikhin–Turaev TQFTs II

Abstract In this talk, I will define ribbon and modular categories, and show how modular categories give rise to representations of the modular group SL(2,Z) using the graphical calculus introduced last time. Time permitted, I will explain how to generalize the construction to obtain a TQFT for closed surfaces.

Date Oct 17, 2018

Speaker Joshua Sabloff

Title Length and width Lagrangian cobordisms

Abstract In this talk, I will discuss two measurements of Lagrangian cobordisms between Legendrian submanifolds in symplectizations: their length and their relative Gromov width. The Gromov width, in particular, is a fundamental global invariant of symplectic manifolds, and a relative version of that width helps understand the geometry of Lagrangian submanifolds of a symplectic manifold. Lower bounds on both the length and the width may be produced by explicit constructions; this talk will concentrate on upper bounds that arise from a filtered version of Legendrian contact homology, a Floer-type invariant. This is joint work with Lisa Traynor.

Date Oct 24, 2018

Speaker Scott Baldridge

Title TBA

Abstract TBA

Date Oct 31, 2018

Speaker Matthew Haulmark

Title TBA

Abstract TBA

Date Jan 9, 2019

Speaker Genevieve Walsh

Title TBA

Abstract TBA

Date Jan 30, 2019

Speaker Francesco Lin

Title TBA

Abstract TBA

Date Mar 27, 2019

Speaker Tye Lidman

Title TBA

Abstract TBA