Western Hemisphere Virtual Symplectic Seminar (WHVSS)

Fall 2021

Mission Statement

The mission of the WHVSS is to increase access to mathematical research and disseminate recent results in a collegial and respectful environment.

Please suggest your thesis students with current research here as speakers, or any other speakers you recommend.



Mohammed Abouzaid (Columbia), Nate Bottman (Max Planck),
Catherine Cannizzo (Simons Center), Sheel Ganatra (USC), Kyler Siegel (USC)

Schedule and Zoom info

In Fall 2021, our seminar meets online Fridays at 12 pm ET.
Zoom Link: https://columbiauniversity.zoom.us/j/96547665252?pwd=T0pOb28vM2JJSnRYM2RjeFBhWU96QT09
Meeting ID: 965 4766 5252
Passcode: 310229

Zoom meetings open 15 minutes before the talk begins.
Talks are 1 hour, followed by a 10-15 min Q&A and an informal discussion session.

Preceding the talk, we will host an informal symplectic tea each Friday on gather.town from 11:45 am - 12 pm ET at the following URL: https://gather.town/app/abBT3vhSL9vD0zbL/virtualsymplectictea

To receive announcements of talks, please join our email listerv.

Notes & Videos

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Here is our GCal which you may add to your own calendar.

Speaker titles and abstracts

September 17, 12 pm ET: Caitlin Leverson (Bard College) - Lagrangian Realizations of Ribbon Cobordisms

Abstract: Similarly to how every smooth knot has a Legendrian representative (in fact, infinitely many different representatives), in this talk we will discuss why every ribbon cobordism has a Legendrian representative. Meaning, if $C$ is a ribbon cobordism in $[0,1]\times S^3$ from the link $K_0$ to $K_1$, then there are Legendrian realizations $\Lambda_0$ and $\Lambda_1$ of $K_0$ and $K_1$, respectively, such that $C$ may be isotoped to a decomposable Lagrangian cobordism from $\Lambda_0$ to $\Lambda_1$. We will also give examples of some interesting constructions of such decomposable Lagrangian cobordisms. This is joint work with John Etnyre.

September 24, 12 pm ET: Shaoyun Bai (Princeton University) - Rouquier dimension, quantitative intersection of skeleta and Orlov’s conjecture

Abstract: For a given triangulated category, its Rouquier dimension is defined to be the minimal generation time of all of its split generators shifted down by 1. The main objects of this talk are the Rouquier dimensions of derived wrapped Fukaya categories of Weinstein manifolds/sectors. In particular, I will explain two results among some others:

  1. Given a Weinstein manifold of dimension 2n, if its wrapped Fukaya category admits a homological section, then any generic push-off of its skeleton by a compactly supported Hamiltonian diffeomorphism intersects its skeleton at least at n points.

  2. Orlov’s conjecture which relates the Krull dimension of a variety to the Rouquier dimension of its derived category holds even for certain singular complex surface.

This is a joint work with Laurent Cote.

October 1, 12 pm ET: Shamuel Auyeung (Stony Brook University) - Local Lagrangian Floer Homology of Quasi-Minimally Degenerate Intersections

Abstract: Given two Lagrangian submanifolds, if they intersect cleanly along a submanifold, then, by the work of Pozniak, their local Lagrangian Floer homology is isomorphic to the singular homology of the submanifold. Moreover, as Seidel observed, if the Lagrangian intersection is decomposable into disjoint clean intersections, there is a local-to-global spectral sequence whose E_1 page depends only on the topology, rather than symplectic geometry, of the intersections. In this talk, we introduce a generalization of clean intersections that is inspired by the notion of minimal degeneracy defined by Kirwan. We will then extract analogues of the above results for such intersections.

October 8, 12 pm ET: Chi Hong Chow (CUHK)

October 15, 12 pm ET

October 22, 12 pm ET: Yuan Gao (University of Georgia)

WHVSS weekly tea

Preceding the talk, we will host an informal symplectic tea each Friday on gather.town from 11:45 am - 12 pm ET at the following URL:


For those of you who haven't used it, gather.town simulates the experience of a large group gathering by allowing you to "walk up to people" in its interface and video chat with the people you are close to.

We are looking forward to seeing you there!