Hello! This is the website for the London Low-Dimensional Topology Seminar, a seminar for low-dimensional topologists at any career stage! We are big proponents of a vertical approach, and our regular attendees range from senior academics to masters' students and final year undergraduates.
We currently meet on Wednesdays at 14:00, with (optional) lunch together beforehand. Rooms and other details will be communicated via email, as these vary week to week.
To be added to the email list, please email one of the organisers :)
Organisers: Alessandro Cigna, KCL (firstname.surname@kcl.ac.uk), Xander Povey, Imperial (firstname.surname23@imperial.ac.uk) and Maartje Wisse, LSGNT (firstname.surname@kcl.ac.uk)
15th October: Steven Sivek, Imperial College London
Title: Ribbon concordance and fibered predecessors
Abstract: Ribbon concordance defines an interesting relation on knots. In his initial work on the topic, Gordon asked whether it is a partial order, and this question was open for over 40 years until Agol answered it affirmatively in 2022. However, we still don’t know many basic facts about this partial order: for example, does any infinite chain of ribbon concordances eventually stabilize? Even better, if we fix a knot in the 3-sphere, are there only finitely many knots that are ribbon concordant to ? I’ll talk about joint work with John Baldwin toward these questions, in which we use tools from both Heegaard Floer homology and hyperbolic geometry to say that at the very least, there are only finitely many fibered hyperbolic knots ribbon concordant to.
22nd October: Misha Schmalian, Oxford University
Title: Uniqueness of Dehn Surgery
Abstract: Dehn Surgery is an operation that allows us to describe any three-manifold via a framed link in the three-sphere. How unique is such a description? Recently, there has been substantial progress and attention on questions of this nature. In this talk I will:
Give an introduction to Dehn surgery problems and how tackle them using Geometrization;
Discuss some recent and some upcoming work with Marc Kegel on this topic;
Give a longer exposition of open questions in the area (not all of which look impossible).
29th October: Maartje Wisse, LSGNT/King's College London
Title: The Dowlin Spectral Sequence for Dummies
Abstract: Rasmussen's 2005 conjecture that there should be a spectral sequence from Khovanov Homology to Knot Floer Homology was fully proved by Dowlin in 2018, following on from various similar earlier results. In this talk I will cover the motivation to build such an object, as well as an outline of the arguments used in Dowlin's construction. If time allows I will lay out the work I am doing with this. This is intended to be an overview talk and will be as light on the details as is possible!
5th November: No seminar for KCL Reading Week!
12th November: Gheehyun Nahm, Princeton University
Title: TBA
Abstract: TBA
19th November: Selim Ghazouani, UCL
Title: TBA
Abstract: TBA
26th November: Soheil Azarpendar, University of Oxford
Title: TBA
Abstract: TBA
3rd December: TBA, TBA
Title: TBA
Abstract: TBA
10th December: Abigail Hollingsworth, University of Warwick
Title: TBA
Abstract: TBA
17th December: TBA, TBA
Title: TBA
Abstract: TBA
For the seminar's 2024-2025 program, please click here (full credit and thanks to Laura Wakelin!)