English
Related papers

Related papers: A fast algorithm for calculating $s$-invariants

200 papers

We introduce a diagrammatic approach to Rasmussen's $s$-invariant, based on Bar-Natan's reformulation of Khovanov homology for tangles and cobordisms. This method enables a local computation of $s$ from a tangle decomposition of a knot…

Geometric Topology · Mathematics 2025-08-11 KeeTaek Kim , Taketo Sano

We use the knot homology of Khovanov and Lee to construct link concordance invariants generalizing the Rasmussen $s$-invariant of knots. The relevant invariant for a link is a filtration on a vector space of dimension $2^{|L|}$. The basic…

Geometric Topology · Mathematics 2012-08-14 John Pardon

We adapt Bar-Natan's scanning algorithm for fast computations in (even) Khovanov homology to odd Khovanov homology. We use a mapping cone construction instead of a tensor product, which allows us to deal efficiently with the more…

Geometric Topology · Mathematics 2022-09-07 Dirk Schuetz

We introduce a refinement of Bar-Natan homology for involutive links, extending the work of Lobb-Watson and Sano. We construct a new suite of numerical invariants and derive bounds for the genus of equivariant cobordisms between strongly…

Geometric Topology · Mathematics 2025-07-21 Maciej Borodzik , Irving Dai , Abhishek Mallick , Matthew Stoffregen

We show that the order of torsion homology classes in Bar-Natan deformation of Khovanov homology is a lower bound for the unknotting number. We give examples of knots that this is a better lower bound than |s(K)/2|, where s(K) is the…

Geometric Topology · Mathematics 2019-09-18 Akram Alishahi

We show that Rasmussen's invariant of knots, which is derived from Lee's variant of Khovanov homology, is equal to an analogous invariant derived from certain other filtered link homologies.

Geometric Topology · Mathematics 2012-07-06 Marco Mackaay , Paul Turner , Pedro Vaz

We define a Rasmussen $s$-invariant over the coefficient ring of the integers, and show how it is related to the $s$-invariants defined over a field. A lower bound for the slice genus of a knot arising from it is obtained, and we give…

Geometric Topology · Mathematics 2022-02-02 Dirk Schuetz

We use recently introduced Rasmussen invariant to find knots that are topologically locally-flatly slice but not smoothly slice. We note that this invariant can be used to give a combinatorial proof of the slice-Bennequin inequality.…

Geometric Topology · Mathematics 2018-06-19 Alexander N. Shumakovitch

We calculated the rational Khovanov homology of some class of pretzel knots, by using the spectral sequence constructed by P. Turner. Moreover, we determined the Rasmussen's s-invariant of almost of pretzel knots with three pretzels.

Quantum Algebra · Mathematics 2007-05-23 Ryohei Suzuki

We describe an algorithm that can effectively calculate the $s$-invariant of a link as defined by Beliakova and Wehrli. Our computations show that this cannot be done by merely calculating the $E_\infty$-page of the Bar-Natan--Lee--Turner…

Geometric Topology · Mathematics 2025-08-18 Dirk Schuetz

In a previous paper we constructed a spectrum-level refinement of Khovanov homology. This refinement induces stable cohomology operations on Khovanov homology. In this paper we show that these cohomology operations commute with cobordism…

Geometric Topology · Mathematics 2014-05-08 Robert Lipshitz , Sucharit Sarkar

We prove formulae for the $\mathbb{F}_2$-Rasmussen invariant of satellite knots of patterns with wrapping number 2, using the multicurve technology for Khovanov and Bar-Natan homology developed by Kotelskiy, Watson, and the second author. A…

Geometric Topology · Mathematics 2025-10-01 Lukas Lewark , Claudius Zibrowius

We use the Mackaay-Vaz universal $sl(3)$-link homology to deepen the study of $s$-invariants on Khovanov's link homology associated to $sl(3)$. Such $s$-invariants have already been studied by Lobb and Wu in characteristic 0 and we show how…

Geometric Topology · Mathematics 2025-08-18 Dirk Schuetz

Khovanov homology is a topological knot invariant that categorifies the Jones polynomial, recognizes the unknot, and is conjectured to appear as an observable in $4D$ supersymmetric Yang--Mills theory. Despite its rich mathematical and…

Geometric Topology · Mathematics 2025-01-27 Alexander Schmidhuber , Michele Reilly , Paolo Zanardi , Seth Lloyd , Aaron Lauda

The paper contains an essentially self-contained treatment of Khovanov homology, Khovanov-Lee homology as well as the Rasmussen invariant for virtual knots and virtual knot cobordisms which directly applies to classical knot and classical…

Geometric Topology · Mathematics 2022-04-20 Heather A. Dye , Aaron Kaestner , Louis H. Kauffman

We investigate the behaviour of Rasmussen's invariant $s$ under the sharp operation on knots and obtain a lower bound for the sharp unknotting number. This bound leads us to an interesting move that transforms arbitrary knots into…

Geometric Topology · Mathematics 2007-05-23 Sebastian Baader

Kronheimer and Mrowka introduced a new knot invariant, called $s^\sharp$, which is a gauge theoretic analogue of Rasmussen's $s$ invariant. In this article, we compute Kronheimer and Mrowka's invariant for some classes of knots, including…

Geometric Topology · Mathematics 2019-08-15 Sherry Gong

We continue to develop the tensor-algebra approach to knot polynomials with the goal to present the story in elementary and comprehensible form. The previously reviewed description of Khovanov cohomologies for the gauge group of rank N-1=1…

High Energy Physics - Theory · Physics 2015-06-17 V. Dolotin , A. Morozov

Given a knot, we ask how its Khovanov and Khovanov-Rozansky homologies change under the operation of introducing twists in a pair of strands. We obtain long exact sequences in homology and further algebraic structure which is then used to…

Geometric Topology · Mathematics 2014-08-01 Andrew Lobb

We construct a mixed invariant of non-orientable surfaces from the Lee and Bar-Natan deformations of Khovanov homology and use it to distinguish pairs of surfaces bounded by the same knot, including some exotic examples.

Geometric Topology · Mathematics 2025-07-08 Robert Lipshitz , Sucharit Sarkar
‹ Prev 1 2 3 10 Next ›