Skip to content
# Events for 11/04/2020 from all calendars

## Noncommutative Geometry Seminar

## Probability Seminar

## Topology Seminar

## Student/Postdoc Working Geometry Seminar

**Time: ** 1:00PM - 2:00PM

**Location: ** Zoom 942810031

**Speaker: **Rudy Rodsphon, Northeastern University

**Title: ***A KK-theoretical perspective on quantization commutes with reduction*

**Abstract: **We propose a reframing of Paradan--Vergne's approach to the quantization commutes with reduction problem in KK-theory, more especially the index theoretic part that leads to their "Witten non-abelian localization formula". While our method is similar to theirs at least in spirit, interesting conceptual simplifications occur, and it makes the relationship to
Ma--Tian--Zhang's analytic methods quite apparent.
Time permitting, I'll also sketch another possible way to derive this localization formula, which is purely functorial.

**URL: ***Event link*

**Time: ** 2:00PM - 3:00PM

**Location: ** Zoom

**Speaker: **Maria Gordina, University of Connecticut

**Title: ***Ergodicity for Langevin dynamics with singular potential*

**Abstract: **We discuss Langevin dynamics of N particles on R^d interacting through a singular repulsive potential, such as the Lennard-Jones potential, and show that the system converges to the unique invariant Gibbs measure exponentially fast in a weighted Sobolev norm. The proof relies on an explicit construction of a Lyapunov function using a modified Gamma calculus. In contrast to previous results for such systems, our results imply geometric convergence to equilibrium starting from an essentially optimal family of initial distributions. This is based on the joint work with F. Baudoin and D. Herzog.

**Time: ** 4:00PM - 5:00PM

**Location: ** Zoom

**Speaker: **Sanjay Kumar, Michigan State University

**Title: ***Fundamental shadow links realized as links in the 3-sphere*

**Abstract: ** In this talk, I will discuss two conjectures which relate quantum topology and hyperbolic geometry. Chen and Yang conjectured that the asymptotics of the Turaev-Viro invariants determine the hyperbolic volume of the 3-manifold, and Andersen, Masbaum, and Ueno (AMU) conjectured for a surface that the asymptotics of the quantum representations reflect certain geometric properties of the mapping class group. For a manifold M(f) constructed as the mapping tori of an element f in the mapping class group, Detcherry and Kalfagianni showed that M(f) satisfying the Turaev-Viro invariant volume conjecture implies that f satisfies the AMU conjecture. Using techniques from Turaev's shadow theory, I construct infinite families of links in the 3-sphere with complement homeomorphic to the complement of fundamental shadow links which are a class of links in connected sums of S^2 times S^1 that satisfy the Turaev-Viro invariant volume conjecture. Through homeomorphisms, these link complements in S^3 can be realized as the mapping tori for explicit elements in the mapping class group providing families that satisfy the AMU conjecture. Video recording is available at https://tamu.zoom.us/rec/share/NVDt4tmOzD6DyGdOfO8XTjBCMBG0d_BK4grFJPN35hrSa7b-N_0rD1MS_OfLEOWK.OV72bu9Mc4g3cwyL (Access Password: 13TuT+XF)

**Time: ** 11:00PM - 12:00PM

**Location: ** zoom

**Speaker: **R. Geng, TAMU

**Title: ***The variety of commuting matrices and geometric rank*