Lukas Lewark
Talks

2023

April 27th, at the Séminaire de Topologie et Géométrie in Geneva: Untwisting and surfaces in 4-space.

February 27th – March 3, at the Baby geometri seminar in Pisa: Minicourse An introduction to Khovanov homology and its applications.

February 2nd, at the Kepler Kolloquium in Regensburg: Untwisting and surfaces in 4-space.

January 24th, at the Oberwolfach Workshop "Morphisms in Low Dimensions": The joy of not being a PID.

2022

December 21st, at the Oberseminar Geometrie in Fribourg: Unknotting, untwisting and surfaces in 4-space.

December 15th, at the Zurich Topology Seminar: Rasmussen invariants of Whitehead doubles and other satellites.

December 8th, at the Kolloquium of the Graduiertenkolleg 2491 Fourier Analysis and Spectral Theory in Göttingen: On Khovanov homology: a combinatorial construction with geometric applications.

October 25th, at the BIRS Workshop about Using Quantum Invariants to do Interesting Topology in Oaxaca: Rasmussen invariants of Whitehead doubles and other satellites. video Video.

May 18th, at the Georgia Topology Conference in Athens (I'll attend online): Khovanov homology and rational unknotting. video Video.

February 8th, at Notre Dame Topology Seminar: Khovanov homology and rational unknotting.

February 3rd, at the conference Recent developments in link homology theories at the SwissMAP Research Station: Khovanov homology and rational unknotting.

January 12th, at Oberseminar Globale Analysis of the University of Regensburg:
Khovanov homology and rational unknotting.

2021

March 25th, at the informal weekly LKS seminar: Sperner's lemma.

March 19th, at a block seminar on 3-manifolds organized by Raphael Zentner: Murasugi sums and fibered links (talk shared with Filip Misev).

March 9th, at a weekly online seminar on 4-manifolds of the MPIM Bonn: S-equivalence of matrices and isometries of linking forms (talk shared with Anthony Conway).

2020

December 21st, at the HIOB seminar of the Regensburg SFB: Khovanov homology: a combinatorial tool with geometric applications.

December 15th, at a weekly online seminar on 4-manifolds of the MPIM Bonn: Various characterizations of the Z-slice genus.

May 29th, at the CIRGET Geometry and Topology Seminar: Squeezed knots. video Video.

April 16th, at the [K-OS] Knot Online Seminar: Unknotting and cobordism distances. video Video.

2019

October 24th, at the Kepler Kolloquium in Regensburg:
Quantum invariants, knot concordance and unknotting.

September 16th, at the Workshop on 4-manifolds at the MPIM:
Untwisting torus knots.

June 18th, at the conference Knot concordance and low-dimensional manifolds in Le Croisic:
Concordance and Khovanov-Rozansky homologies.

May 9th, at the workshop at Matemale:
Bridge trisections of knotted surfaces in S^4 (on the paper by Meier and Zupan).

April 16th, at the Topology Seminar of the IMJ in Paris:
Unknotting and Surfaces.

February 18th, at the Mathematical Colloquium of Bern:
Unknotting and Surfaces.

January 18th, at the Institut Fourier, Grenoble:
Linking pairings and unknotting numbers.

2018

November 27th, at the Topology Seminar at the Math Institute of the University of Bonn:
Linking pairings and unknotting numbers.

November 13th, at the Seminar Algebra and Geometry of the University of Basel:
Positivity, Graphs and Unknotting.

April 27th, at the Knot theory seminar at Warsaw University:
Genus and Unknotting.

April 17th, at the Seminar of the SFB Higher Invariants at Regensburg:
Balanced unknotting, Blanchfield form, and surfaces in 3- and 4-space.

March 15th, at the Boston College Geometry/Topology seminar:
Balanced unknotting, Blanchfield form, and surfaces in 3- and 4-space.

March 7th, at the conference Quantum Knot Homology and Supersymmetric Gauge Theories at the Aspen Center for Physics:
Upsilon-like invariants from Khovanov-Rozansky sl(n) homologies.

2017

November 27th, at the Séminaire Géométrie, Dynamique et Topologie of the Institut de Mathématiques de Marseille:
L'homologie de Khovanov-Rozansky entre les nœuds positifs et négatifs.

November 24th, at the Séminaire Topologies of the Institut Montpelliérain Alexander Grothendieck:
Graphes planaires et clôtures de tresses positives.

June 27th, at the workshop Quantum topology and categorified representation theory at the Isaac Newton Institute in Cambridge:
An Upsilon-like invariant from Khovanov-Rozansky homology. video Video.

April 27th, at the Séminaire de Topologie et Géométrie in Geneva:
L'homologie de Khovanov-Rozansky entre les nœuds positifs et négatifs.

April 5th, at the University of Zurich:
Khovanov-Rozansky homology in between positive and negative knots.

March 27th, at the Séminaire quantique in Strasbourg:
Khovanov-Rozansky homology in between positive and negative knots.

February 16th, at the seminar of the programme Homology theories in low dimensional topology at the Isaac Newton Institute in Cambridge:
The Seifert form's optimal bounds for slice genera. video Video.

2016

October 26th, at the Seminar on knot concordance and 4-manifolds of the Topology Trimester at the HIM (Bonn):
Slice genus bounds from the Seifert form.

May 4th, at Oberseminar Globale Analysis of the University of Regensburg:
Seifert Form and Slice Genus of Knots.

February 23rd, at the BIRS Workshop about Synchronizing Smooth and Topological 4-Manifolds in Banff:
Upper bounds for the topological slice genus of knots. video Video.

2015

September 15th, at the Topology Seminar of the IMJ in Paris:
Théorie des nombres et genre slice topologique des nœuds.

June 13th, at the special session Categorification of Quantum groups, Representations and Knot Invariants of the Joint AMS-EMS-SPM meeting in Porto:
New quantum obstructions to sliceness.

April 28th, at the Zurich Graduate Colloquium:
What is... a knot's slice genus?

April 15th, at the Seminar "Quantum Groups and Low-Dimensional Topology" of the University Zurich:
Khovanov-Rozansky homologies with non-standard potentials.

2014

November 19th, at the Colloquium of Tohoku University:
The asymptotic slice genus of alternating knots.

September 22nd, at the Mathematical Colloquium of Bern:
Quantum obstructions to sliceness of knots.

September 19th, at the Knot Theory Session-Symposium of the DMV-PTM Joint Meeting in Poznań:
Khovanov-Rozansky homologies induce non-additive four-ball genus bounds.

September 17th, at the Oberwolfach Workshop "Topologie":
Khovanov-Rozansky homologies induce non-additive four-ball genus bounds.

July 2nd, in Regensburg:
Neue Schranken für das vierdimensionale Geschlecht.

June 19th, at the Institut de Mathématiques de Bourgogne:
De nouvelles obstructions quantiques au genre slice des nœuds.

May 22nd, at the MPI-Oberseminar:
New quantum obstructions to sliceness.

April 28th, at the Oberseminar Topologie of the WWU Münster:
New quantum obstructions to smooth sliceness of knots.

January 21st, at the Topology Seminar of the George Washington University:
More on Khovanov-Rozansky concordance invariants.

January 19th, at Knots in Washington XXXVII:
The Khovanov-Rozansky concordance invariants.

January 8th, at the Centre for Quantum Geometry of Moduli Spaces, Aarhus:
The Khovanov-Rozansky concordance invariants.

2013

November 28th, at the University of Geneva Séminaire de Topologie et Géométrie:
The Khovanov-Rozansky concordance invariants.

November 6th, at the Topology Reading Group, Durham:
The Khovanov-Rozansky concordance invariants.

November 8th, at the London Topology and Geometry Seminar:
The Khovanov-Rozansky concordance invariants.

October 24th, at the Boston College Geometry/Topology seminar:
The Khovanov-Rozansky concordance invariants.

October 22th, at the UC Davis Geometry/Topology seminar:
The Khovanov-Rozansky concordance invariants.

October 22th, at the UC Davis Student-Run Geometry/Topology seminar:
An introduction to the Khovanov-Rozansky homologies.

October 20th, at the Joint Los Angeles Topology Seminar:
The Khovanov-Rozansky concordance invariants.

October 17th, at Stony Brook's Thursday Topology Seminar:
The Khovanov-Rozansky concordance invariants.

October 14th, at an informal seminar at Columbia University:
The Khovanov-Rozansky concordance invariants.

September 26th, at the University of Zurich:
The Khovanov-Rozansky concordance invariants.

June 17th, at the Pure Maths Colloquium, Durham:
Knot concordance, slice-torus homomorphisms and the Khovanov-Rozansky homologies.

June 5, at the Workshop on "Geometry and topology of smooth 4-manifolds", Bonn:
Distinguishing the Khovanov-Rozansky knot concordance invariants.

May 6th, at the Université catholique de Louvain:
The Rasmussen and other slice-torus knot concordance invariants.

April 26th, at Young Topology Meeting:
Knot Concordance.

April 5th, at Swiss Knots:
The Khovanov-Rozansky concordance invariants.

2012

October 8th, in the working group TQFT et catégorification (IMJ):
Les bornes au genre lisse fournies par les homologies sl(n) sont distinctes.

February 29th, at the winterschool of la Llagonne, together with Pierre Dehornoy:
L'espace de Teichmüller et sa compactification.

February 6th, at the conference Topologie quantique et catégorification at the CIRM:
sl3-link homology and a Lower Bound for the Slice Genus and
sl3-link homology of Knotted Webs and of their Branched Klein-Coverings.

2011

March, at the winterschool of la Llagonne:
Des nouvelles manières de calculer l'invariant de concordance de Rasmussen.

2010

December 9th, in an informal seminar (IMJ):
Qu'est-ce qu'une suite spectrale?

October 11th, in the working group TQFT et Catégorification:
Calcul de l'homologie de Khovanov et de l'invariant de Rasmussen.

April 15th, in an informal seminar (IMJ):
La sphère de Poincaré.

March 3rd and 4th, together with Louis-Hadrien Robert and Christian Blanchet, at the winterschool of la Llagonne:
Topological moduli spaces of knots about Allen Hatcher's draft of the same name.

February 22nd, in the working group Algèbre et Topologie quantiques:
Représentation de U*-> sur la 2-catégorie des drapeaux about §6 of the paper of Khovanov and Lauda, see below.

February 15th, in the working group Algèbre et Topologie quantiques:
Cohomologie des variétés de drapeaux à n pas about §5 of Khovanov and Lauda's paper A diagrammatic approach to categorification of quantum groups III.

Last update: 22 April 2024.