[K-OS] Knot Online Seminar
[K-OS] is an online research seminar which focuses on knot
theory and low-dimensional topology. Talks will be delivered
by authors of recent arXiv articles of significant interest.
It happens the 3rd Thursday of every month
from 16:15 to 17:15
(
CET/CEST Berlin,
Brussels, Madrid, Paris, Rome, Vienna, Warsaw, Zurich)
on
Zoom.
It is organized by
Alexandra
Kjuchukova,
Lukas
Lewark,
Delphine
Moussard
and
Emmanuel
Wagner.
It benefits from logistical support from
the
CNRS, the university
of
Paris and the
ETHZ.
If there is a recent arXiv preprint which you would like to see featured on the seminar, please email the organizers with your suggestion.
The K-OS talks are also listed in a
Google Calendar.
Forthcoming Talks
20 November 2025
- Speaker: Susan Hermiller (University of Nebraska)
- Unknotting number and connected sums (2506.24088).
- Abstract: Unknotting number is a fundamental measure of how complicated a knot is, measuring how far it is from the unknot via crossing changes. It is a challenging invariant to compute, with a vast array of tools applied to its calculation, and many conjectures have grown up around it. In this talk I will discuss three conjectures, each aimed at simplifying the task of computing unknotting numbers. I will describe how our resolution of one of these conjectures several years ago led us recently to resolve another – the (non)additivity of unknotting number under connected sum. This is joint work with Mark Brittenham.
18 December 2025
