# Math Calendar

### Upcoming Events

## Qualifying Examination

Minh Quan Hoang Vu

Email: minh.quan.h.vu@vanderbilt.edu

## Topology & Group Theory Seminar

## Proper proximality for groups acting on trees

Srivatsav Kunnawalkam Elayavalli (Vanderbilt)

Topology & Group Theory Seminar page for Zoom meeting information

I will discuss joint work with Changying Ding, where we show that many groups acting on trees are properly proximal in the sense of Boutonnet-Ioana-Peterson

## Subfactor Seminar

## Spin model subfactors

Michael Montgomery, Vanderbilt University

Complex Hadamard matrices generate a class of irreducible hyperfinite subfactors with integer Jones index coming from spin model commuting squares. I will prove a theorem that establishes a criterion implying that these subfactors have infinite depth. I then show that Paley type II and Petrescu’s continuous family of Hadamard matrices yield infinite depth subfactors. Furthermore, infinite depth subfactors are a generic feature of continuous families of complex Hadamard matrices. In this talk I will present an outline for the proof of these results.

## Computational Analysis Seminar

## Title- TBD

Rocío Díaz Martín, Vanderbilt University

Computational Analysis Seminar page for Zoom meeting information

## PDE Seminar

## PDE Seminar- Title- TBD

Elena Giorgi, Columbia University

PDE Seminar

## Computational Analysis Seminar

## Title TBD

Ron Levie, University of Munich

Computational Analysis Seminar page for Zoom meeting information

## Topology & Group Theory Seminar

## Growth Of Dehn Twist and Pseudo-Anosov Conjugacy Classes in Teichmüller Space

Jiawei Han (Vanderbilt)

Topology & Group Theory Seminar page for Zoom meeting information

Abstract: Athreya, Bufetov, Eskin and Mirzakhani have shown the number of mapping class group lattice points intersecting a closed ball of radius $R$ in Teichmüller space is asymptotic to $e^{hR}$, where $h$ is the dimension of the Teichmüller space. In contrast, we first show the number of Dehn twist lattice points intersecting a closed ball of radius $R$ is coarsely asymptotic to $e^{hR/2}$. Moreover, we show the number of all multi-twists lattice points intersecting a closed ball of radius $R$ grows coarsely at least at the rate of $R e^{hR/2}$. Furthermore, we show for any pseudo-Anosov mapping class $f$, there exists a power $n$, such that the number of lattice points of the $f^n$ conjugacy class intersecting a closed ball of radius $R$ is coarsely asymptotic to $e^{hR/2}$. Finally, we could discuss a few open questions and a conjecture. The main results in this talk are from author’s papers arXiv:2105.08624 and arXiv:2105.08640.

## Subfactor Seminar

## Subfactor Seminar- Title- TBD

Dan-Virgil Voiculescu, UC Berkeley

Zoom ID 94393956397 Subfactor Seminar page for Zoom meeting information

## Topology & Group Theory Seminar

## Title- TBD

Jiawei Han (Vanderbilt)

Topology & Group Theory Seminar page for Zoom meeting information

## Subfactor Seminar

## Subfactor Seminar-Title TBD

Mikael Rordam, University of Copenhagen

Zoom ID 94393956397 Subfactor Seminar page for Zoom meeting information

## PDE Seminar

## PDE-Seminar- Title- TBD

Katrina Morgan, Northwestern University

PDE Seminar page for Zoom meeting information

## Computational Analysis Seminar

## Title- TBD

Alex Cloninger, University of California – San Diego

Computational Analysis Seminar page for Zoom meeting information

## Subfactor Seminar

## Subfactor Seminar- Title TBD

Changying Ding, Vanderbilt University

Zoom ID 94393956397 Subfactor Seminar page for Zoom meeting information

## PDE Seminar

## PDE Seminar- Title- TBD

Federico Pasqualotto, Duke University

PDE Seminar

## Subfactor Seminar

## Subfactor Seminar- Title TBD

Corey Jones, North Carolina State University

Zoom ID 94393956397 Subfactor Seminar page for Zoom meeting information

## Computational Analysis Seminar

## Title- TBD

Yvonne Ou, University of Delaware

Computational Analysis Seminar page for Zoom meeting information

## Subfactor Seminar

## Subfactor Seminar- Title TBD

James Tener, ANU Mathematical Sciences Institute

Zoom ID 94393956397 Subfactor Seminar page for Zoom meeting information