GT GAPS

Geometric Topology Grad and Postdoc Seminar

GT GAPS is an online seminar (via Zoom) for graduate students and postdoctoral scholars studying geometric topology. In Spring 2024, we meet Fridays 9 am PT/ 12pm EDT/ 5pm CET/ 9:30pm IST.

Each week, someone (a student or postdoc) gives a talk by Zoom that lasts about one hour. Many talks are expository and very informal. Participants are encouraged to ask many questions and potentially break into discussion, depending on the speaker's preference.

The organizers of this seminar are Clair Xinle Dai, Vivian He, and Aru Mukherjea. You can email us if you have any questions. Check out the current or old calendars to get an idea of potential topics.

If you are interested in getting reminder emails on Thursdays with the Zoom info, please sign up here!

Next Speaker

Speaker: ​​​​​​Jaewon Chang (Harvard)

Title: ​Canonical basis of the wrapped Floer cohomology

Abstract: ​Beginning from the observation made by physicists that Calabi-Yau manifolds come in pairs of "mirror dual" families, the mirror symmetry conjectures were proposed as a way to formulate the intricate connection between symplectic geometry on a space and algebraic geometry on its dual. One version of this is the homological mirror symmetry conjecture, which implies a correspondence between Lagrangian Floer chain complexes and corresponding Hom spaces in the category of coherent sheaves.
Studying these chain complexes and their homology groups can be challenging due to the multiple ways to calculate or describe them. In particular, while there are vast studies and predictions of canonical bases of the cohomology rings on the algebraic side, the descriptions of Lagrangian Floer cohomology rings often fail to give a distinguished basis.
In this talk, I will discuss the case of certain Lagrangians in (C*)², and describe distinguished bases of their (wrapped) Floer cohomology. Under mirror symmetry, this will also give distinguished bases of the ring of functions on P¹ minus 4 points.

Date and Time: ​April 12, 9 am PT/ 12pm EDT/ 5pm CET/ 9:30pm IST.

Winter 2024

Date Speaker Title
Feb 2 Porter Morgan (UMass Amherst) Nonorientable broken Lefschetz fibrations
Feb 9 Michael Kopreski (Utah) Multiarc and curve graphs are classified by their witnesses
Feb 16 Annette Karrer (Fields Institute) Subgroups arising from connected components in the Morse boundary
Feb 23 Mihail Arabadji (UMass Amherst) The Nielsen realization for non-spin 4-manifolds
Mar 1 Ismael Sierra (Toronto) Homological stability of even and odd symplectic groups
Mar 8 Qianhe Qin (Stanford) Discovering n-Friends Through n-RBG Links
Mar 15 Inhyeok Choi (KIAS) Growth of normal subgroups of a hyperbolic group
Mar 29 Hannah Turner (Georgia Tech) Fractional Dehn twists and left-orders on groups
Apr 12 Jaewon Chang (Harvard)

2024 Schedule

Date Speaker Title
Mar 1 Ismael Sierra (Toronto) Homological stability of even and odd symplectic groups
Feb 23 Mihail Arabadji (UMass Amherst) The Nielsen realization for non-spin 4-manifolds
Feb 16 Annette Karrer (Fields Institute) Subgroups arising from connected components in the Morse boundary
Feb 9 Michael Kopreski (Utah) Multiarc and curve graphs are classified by their witnesses
Feb 2 Porter Morgan (UMass Amherst) Nonorientable broken Lefschetz fibrations

2022 Schedule

Date Speaker Title
Dec 1 Kai Nakamura (UT Austin) Blowing up and down with knot traces
Nov 17 Ethan Dlugie (Berkeley) The Burau Representation and Shapes of Polyhedra
Nov 10 Alex Manchester (Rice) (n)-solvability and satellite operators
Oct 27 Nicholas Cazet (UC Davis) Applications of the Quandle Cocycle Invariant
Oct 20 Hongyi Liu (Berkeley) A compactness theorem for hyperkahler 4-manifolds with boundary
Oct 13 Alice Hedenlund (Uppsala) Seiberg-Witten Floer Theory and Twisted Parametrised Spectra
Oct 5 Noah Porcelli (Imperial) Lagrangian monodromy and string topology
Sep 29 Giovanni Italiano (SNS di Pisa) Hyperbolic 5-manifolds fibering over the circle
Sep 22 Randy Van Why (Northwestern) The symplectic and contact geometry of symplectic divisors in dimension 4
Aug 25 Tina Torkaman (Harvard) Systole and intersection number on compact hyperbolic surfaces
Aug 18 Roman Krutowski (UCLA) Maslov index formula in Heegaard Floer homology
Aug 11 Vivian He (Toronto) Generalizing the Gromov Boundary
Jul 28 Jiakai Li (Harvard) Construction of instantons on S^4
Jul 21 John Nicholson (Imperial) The topology of 2-complexes
Jul 14 Neža Žager Korenjak (UT Austin) Constructing proper affine actions
Jul 7 Riccardo Pedrotti (UT Austin) Fixed point Floer cohomology of a Dehn twist in a monotone setting and in more general contexts
Jun 30 James Hughes (UC Davis) An introduction to Legendrian weaves
May 5 Alex Nolte (Rice) Higher Complex Structures and Hitchin Components
Apr 28 Gary Guth (Oregon) Ribbon Homology Cobordisms and Link Floer Homology
Apr 21 Ethan Farber (Boston College) Fixed-point free pseudo-Anosovs and the cinquefoil
Apr 7 Sara Edelman-Munoz (Rice) The Finitely Generated Intersection Property in 3-manifold Groups
Mar 31 Yi Wang (UPenn) Homotopy type of spaces of circle fibrations
Mar 24 Daren Chen (Stanford) Lasagna algebra and Floer lasagna module
Mar 10 Chaeryn Lee (UIUC) Essential surfaces in the exterior of K13n586
Mar 3 Chi Cheuk Tsang (Berkeley) Veering triangulations and pseudo-Anosov flows
Feb 24 Orsola Capovilla-Searle (UC Davis) Infinitely many planar exact Lagrangian fillings and symplectic Milnor fibers
Feb 17 Patricia Sorya (UQAM) Obstructions to the triangulation of manifolds
Feb 10 Gianluca Faraco (MPIM) Translation surfaces and periods of meromorphic differentials

2021 Schedule

Date Speaker Title
Dec 7 Oğuz Şavk (Boğaziçi) Classical and new plumbings bounding contractible manifolds and homology balls
Nov 30 Sarah Blackwell (UGA) Triple Knot Grid Diagrams
Nov 23 Jonathan Johnson (Oklahoma State) Bi-Orderability and Pretzel Knots
Nov 16 Lisa Lokteva (Glasgow) Surgeries on Iterated Torus Knots Bounding Rational Homology 4-Balls
Nov 9 Shintaro Fushida-Hardy (Stanford) Chopping up 4-manifolds to study embedded surfacesTuesday
Nov 2 Charles Stine (Brandeis) Shake-Slice Knots and the Levine-Tristram Signature
Oct 26 William Stagner (Rice) Filling links in 3-manifolds
Oct 19 Khánh Le (Temple) Left orderability and Dehn surgery
Oct 12 Julian Chaidez (Princeton) Surface diagrams and quantum invariants in low dimensions
Oct 5 Jonathan Zung (Princeton) Universal circles for foliations
Aug 17 Ethan Dlugie (UC Berkeley) Geometry, Topology, and Wallpaper Groups
Aug 10 Hyun Ki Min (Georgia Tech/MIT) Symplectic topology and property R
Aug 3 Casandra Monroe (UT Austin) Deformations of hyperbolic structures on manifolds
Jul 27 Seraphina Lee (Chicago) Finite order elements of mapping class groups
Jul 20 Dionne Ibarra (George Washington) On framings of links in 3-manifolds
Jul 13 Shawn Williams (Rice) Higher Order Alexander Modules
Jun 29 Agniva Roy (Georgia Tech) Legendrian Contact Homology and Flow Trees
May 13 Ben Ruppik (MPIM) Homotopy classification of 4-manifolds whose fundamental group is dihedral
May 6 Nicole Yamzon (UIUC) Binomial ideals of domino tilings
Apr 22 Ceren Kose (UT Austin) 3-manifolds that admit exotic fillings
Apr 15 John Chae (UC Davis) Knot complement, series invariants and categorification
Apr 8 Sally Collins (Georgia Tech) Bordered Floer Homology via Immersed Curves
Apr 1 Paula Truöl (ETH Zurich) Positive 3-braid knots, their upsilon invariants and alternation numbers
Mar 25 Aaron Calderon (Yale) Building random hyperbolic surfaces (after Mirzakhani)
Mar 18 Carmen Galaz-García (UCSB) Anosov representations and symmetric spaces
Mar 11 Mac Krumpak (Brandeis) Monopoles and the Froyshov h invariant
Mar 4 Seppo Niemi-Colvin (Duke) Invariance Result for Knot Lattice Homology
Feb 25 Beibei Liu (Georgia Tech) Some applications of Heegaard Floer homology to links in the three-sphere
Feb 18 Tam Cheetham-West (Rice) Some remarks on 4-dimensional geometries
Feb 11 Braeden Reinoso (Boston College) Capping off open books and fractional Dehn twist coefficients
Feb 4 Irving Dai (MIT) Instantons and Homology Cobordism

2020 Schedule

Date Speaker Title
Dec 3 Oğuz Şavk (Boğaziçi) Brieskorn spheres, homology cobordism and homology balls
Nov 19 Agnese Barbensi (Oxford) Knotoids and knotted proteins
Nov 12 Maggie Miller (MIT) Stong's Kervaire-Milnor invariant
Nov 5 Lvzhou (Joe) Chen (UT Austin) Quasimorphisms and group actions
Oct 29 Ludovico Battista (Pisa) A Hyperbolic 4-Manifold with a Perfect Circle-Valued Morse Function
Oct 22 Patrick Naylor (Waterloo) Gluck twists of some roll spun knots are standard (with Hannah Schwartz)
Oct 8 Seungwon Kim (IBS CGP Korea) Turaev genus
Oct 1 Onkar Singh Gujral (Duke) Khovanov homology and cobordisms between split links (with Adam Levine)
Sep 24 Clayton McDonald (Boston College) Doubly slice links (with Duncan McCoy)
Sep 17 Ben Lowe (Princeton) Totally geodesic planes in hyperbolic 3-manifolds
Sep 10 Tyrone Ghaswala (UQAM) The Meyer signature cocycle
Aug 27 Luya Wang (UC Berkeley) ECH, HF and open book decompositions
Aug 20 Terrin Warren (UGA) Slice knots and an interestingly uninteresting example (Piccirillo)
Aug 13 Adam Howard (Montana) Some Examples of Knotted Tori (Boyle)
Aug 6 Robin Gaudreau (Toronto) A direct proof that classical braid groups inject in virtual braid groups
Jul 30 Nickolas Castro (Arkansas) Future Directions of Relative Trisections
Jul 23 Puttipong Pongtanapaisan (U Iowa) Bridge distance of a knot in a 3-manifold
Jul 16 Vitalijs Brejevs (Glasgow) 3-braid closures and rational balls (Simone)
Jul 9 Daniel Hartman (UGA) Morse 2-functions to Kirby diagrams
Jul 2 Josh Wang (Harvard) Floer and Khovanov homologies of band sums
Jun 18 Maggie Miller (Princeton/MIT) Handle-ribbon knots (some joint work with Alex Zupan)
Jun 11 Vincent Longo (UNL) Infinite family of counterexamples to Batson's conjecture
Jun 4 Anubhav Mukherjee (Georgia Tech) Exotic cap on 3-manifolds
May 21 Tam Cheetham-West (Rice) Identifying a hyperbolic 3-manifold via finite quotients (Wilton-Zalesskii)
May 14 Shruthi Sridhar (Princeton) Kontsevich invariants
May 7 Patrick Naylor (Waterloo) Diffeomorphisms of 4D 1- handlebodies (Laudenbach-Poenaru)
Apr 30 Charles Stine (Brandeis) Closed oriented 4-manifolds embed in CP^3 (Ghanwat--Pancholi)
Apr 23 Hannah Schwartz (MPIM) Isotopies of 2-spheres in S^2 x S^2
Apr 16 Tanushree Shah (Glasgow) Classification of contact structures on certain 3-manifolds
Apr 9 Antonio Alfieri (UBC) Symplectic foliations of higher-dimensional manifolds
Apr 2 Ben Ruppik (MPIM) Deeply slice knots
Mar 26 Sarah Blackwell (UGA/MPIM) My (at the moment) fav proof (concerning Legendrian knots)
Mar 19 Maggie Miller (Princeton) Dehn's Lemma
Mar 12 Gabriel Islambouli (Waterloo) Multisections of 4-manifolds
Mar 5 Irving Dai (MIT) Corks + involutive Floer homology
Feb 27 Maggie Miller (Princeton) Knots branched covers bounding rational balls
Feb 13 Danica Kosanović (MPIM) Budney-Gabai (obstruction)
Feb 6 Clayton McDonald (Boston College) Budney-Gabai's non-isotopic 3-balls in S^4 (construction)
Jan 30 Puttipong Pongtanapaisan (U Iowa) Additivity of Morse-Novikov (Ken Baker)
Jan 23 Oliver Singh (Durham) The cork theorem
Jan 16 Jason Joseph (UGA/MPIM) Unknotting numbers of 2-knots in S^4

2019 Schedule

Date Speaker Title
Dec 11 Tam Cheetham-West (Rice) Profinite rigidity for 3-manifolds
Dec 4 Sarah Blackwell (UGA/MPIM) Configuration space integrals for links
Nov 20 Maggie Miller (Princeton/MPIM) Dehn filling vs the Thurston norm
Nov 13 Bill Olsen (UGA/MPIM) Group cohomology
Oct 30 Swapnanil Banerjee (UGA) Morse 2-functions on knotted surfaces
Oct 17 Stefan Mihajlović (CEU) Small exotic 4-manifolds from lines and quadrics in CP2
Oct 10 Puttipong Pongtanapaisan (U Iowa) Something interesting about virtual knots
Oct 3 Jesse Moeller (UNL) Farey diagrams are standard (joint with Román Aranda)
Sep 25 Patrick Naylor (Waterloo/MPIM) Branched covers via trisections
Sep 4 Vincent Longo (UNL/MPIM) "Symmetric ribbon disks," by Paolo Aceto
Aug 13 Charles Stine (Brandeis) Freedman's disk embedding theorem: part 2
Aug 6 Charles Stine (Brandeis) Freedman's disk embedding theorem: part 1
Jul 30 Sarah Blackwell (UGA) Some facts about Legendrian knots
Jul 23 Gabriel Islambouli (UVA/Waterloo) Nielsen Equivalence
Jul 16 Maggie Miller (Princeton) "0-concordance of 2-knots," by Nathan Sunukjian
Jun 25 Clayton McDonald (Boston College) Doubly slicing knots
Jun 11 Vincent Longo (UNL) Tunnel number of 2-knots
Jun 4 Puttipong Pongtanapaisan (U Iowa) Something 3-dimensional
May 28 Román Aranda (U Iowa) Thin position and trisections
May 21 Patrick Naylor (Waterloo) Simplfying the trisection of a Price twist
May 14 Jason Joseph (UGA) Quandle cohomology for 2-knots
May 7 Seungwon Kim (NIMS Korea) Möbius bands in S^3 and B^4
Apr 30 Bill Olsen (UGA) Engel Structures

This website design is based on the previous website of GT GAPS, credited to Tam Cheetham-West, Maggie Miller, and Luya Wang.