This seminar series will take place on UC Berkeley campus, in Evans Hall room 939.

This seminar series will take place on UC Berkeley campus, in Evans Hall room 740.

In this talk, we will discuss joint work with Giuseppe Martone, Filippo Mazzoli, and Tengren Zhang about d-pleated surfaces, which are surface group representations into $.

Zoom Link

Zoom Link

 I will give an update on recent progress in the study of Reeb dynamics on 3-dimensional contact manifolds: existence of Birkhoff sections, count of periodic orbits and Reeb chords. This is joint work with Pierre Dehornoy, Umberto Hryniewicz and Ana Rechtman.

Corlette and Gromov--Schoen established analogues of Margulis superrigidity theorem for lattices in the isometry group of the n-quaternionic hyperbolic space, n>1, and the isometry group of the octonionic hyperbolic plane. In this talk, I will survey some constructions of finitely presented groups with restricted linearity and discreteness properties, obtained from superrigid  hyperbolic lattices. These include constructions of nonlinear hyperbolic groups, hyperbolic groups indiscrete in rank 1 and robustly discrete hyperbolic subgroups of SL(n,C) which fail to be Anosov.

Zoom Link

This week we will resume our discussion on Minsky's Note (Warwick Chp. 5).

Veering triangulations give us a practical way to find and study pseudo-Anosov flows computationally. However, given a manifold, finding a veering triangulation is difficult for many reasons: the triangulations are rigid and can be non-minimal, and the corresponding flows need to be "nice" (no perfect fits, transitive). I will explain how to instead use more flexible triangulations to capture more pseudo-Anosov flows. We use this to find many explicit examples, and then tackle a natural question: when we find a flow, does it have a veering triangulation?

The L-space conjecture predicts that a pseudo-Anosov flow with orientable stable/unstable foliations should induce a left order on the fundamental group. In this talk, we will describe a failed idea to produce such a left order by modifying the universal circle construction. This is joint work with Bojun Zhao and Jonathan Zung.

Zoom Link

This is the continuation of the talk of Rafael Potrie last week. We showed with him in https://arxiv.org/abs/2510.15176  that a pair of transverse foliations by Gromov hyperbolic leaves in a closed 3-manifold either intersects in a leafwise quasigeodesic manner, or it contains a (generalized) Reeb surface. I will talk about the case that if L, E are leaves of the two foliations in the universal cover, then their intersection is connected, that is a single bi-infinite properly embedded arc. This part of the proof at this point needs that leaves are Gromov hyperbolic. The analysis is pretty much independent of part 1, which did not need Gromov hyperbolicity at all, and part 2 uses much more geometric ideas.

Translation: you can still understand most of it if you missed part 1.

Asymptotic dimension is a coarse invariant that was introduced by Gromov to study the "large scale" dimension of a group. In this talk, we will very briefly look at how asymptotic dimension was determined to be finite in the context of mapping class groups of finite type surfaces. We will then move on to the case of infinite type surfaces and classify asymptotic dimension for big mapping class groups.

This seminar series will take place on UC Berkeley campus, in Evans Hall room 939.

This seminar series will take place on UC Berkeley campus, in Evans Hall room 740.

Zoom Link

Zoom Link

Zoom Link

Zoom Link

This seminar series will take place on UC Berkeley campus, in Evans Hall room 939.

This seminar series will take place on UC Berkeley campus, in Evans Hall room 740.

Zoom Link

Zoom Link

Zoom Link

This seminar series will take place on UC Berkeley campus, in Evans Hall room 939.

This seminar series will take place on UC Berkeley campus, in Evans Hall room 740.

Zoom Link

Zoom Link

Zoom Link

Zoom Link

Zoom Link

Zoom Link

Zoom Link

This seminar series will take place on UC Berkeley campus, in Evans Hall room 939.

This seminar series will take place on UC Berkeley campus, in Evans Hall room 740.

Zoom Link

You are cordially invited to attend our End-of-Semester potluck on Wednesday, May 13th from 5:00-7:00pm. We encourage you to bring your family or a guest---the more the merrier!

For those of you who do not know, a 'potluck' party is one in which the food is provided by YOU.  You prepare a dish, such as a salad, a main dish, or a dessert, bringing enough for yourself, your family/guests, and 4 more.  This way, everyone can have a little of each dish.  SLMath will provide beverages.

Zoom Link

Zoom Link

Zoom Link

Zoom Link

Zoom Link

This seminar series will take place on UC Berkeley campus, in Evans Hall room 740.

Zoom Link

Zoom Link