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

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From Khovanov homology, we extract a new lower bound for the Gordian distance of knots, which combines and strengthens the previously existing bounds coming from Rasmussen invariants and from torsion invariants. We also improve the bounds…

Geometric Topology · Mathematics 2024-09-10 Lukas Lewark , Laura Marino , Claudius Zibrowius

We use Lee's work on the Khovanov homology to define a knot invariant s. We show that s(K) is a concordance invariant and that it provides a lower bound for the slice genus of K. As a corollary, we give a purely combinatorial proof of the…

Geometric Topology · Mathematics 2007-05-23 Jacob A. Rasmussen

We introduce new skein invariants of links based on a procedure where we first apply the skein relation only to crossings of distinct components, so as to produce collections of unlinked knots. We then evaluate the resulting knots using a…

Geometric Topology · Mathematics 2019-04-04 Louis H. Kauffman , Sofia Lambropoulou

The Lipshitz-Sarkar stable homotopy link invariant defines Steenrod squares on the Khovanov cohomology of a link. Lipshitz-Sarkar constructed an algorithm for computing the first two Steenrod squares. We develop a new algorithm which…

Geometric Topology · Mathematics 2017-10-06 Andrew Lobb , Patrick Orson , Dirk Schuetz

Computing the Jones polynomial of general link diagrams is known to be $\#$P-hard, while restricting the computation to braid closures on fixed number of strands allows for a polynomial time algorithm. We investigate polynomial time…

Geometric Topology · Mathematics 2026-01-06 Tuomas Kelomäki , Dirk Schütz

A spectral sequence is established, from Bar-Natan's variant of Khovanov homology to a deformation of instanton homology for knots and links. This spectral sequence arises as a specialization of a spectral sequence from a characteristic-2…

Geometric Topology · Mathematics 2019-10-29 P. B. Kronheimer , T. S. Mrowka

We investigate the Khovanov-Rozansky invariant of a certain tangle and its compositions. Surprisingly the complexes we encounter reduce to ones that are very simple. Furthermore, we discuss a "local" algorithm for computing…

Geometric Topology · Mathematics 2008-02-07 Daniel Krasner

We construct a spectral sequence relating the Khovanov homology of a strongly invertible knot to the annular Khovanov homologies of the two natural quotient knots. Using this spectral sequence, we re-prove that Khovanov homology…

Geometric Topology · Mathematics 2025-07-08 Robert Lipshitz , Sucharit Sarkar

Given a link or a tangle diagram, we define algorithmic Morse theoretic simplifications on their Khovanov homology. In contrast to Bar-Natan's scanning algorithm, the cancellations are postponed until the end and performed in one go.…

Geometric Topology · Mathematics 2025-07-22 Tuomas Kelomäki

Recently, Sarkar-Scaduto-Stoffregen constructed a stable homotopy type for odd Khovanov homology, hence obtaining an action of the Steenrod algebra on Khovanov homology with $\mathbb{Z}/2\mathbb{Z}$ coefficients. Motivated by their…

Geometric Topology · Mathematics 2025-10-03 Dirk Schuetz

Sophisticated Khovanov-Rozansky (KhR) description of knot invariants in the fundamental representation can be reformulated in terms of bicomplex with a simple physical meaning. Namely, the counterintuitive matrix factorization is…

High Energy Physics - Theory · Physics 2026-05-05 D. Galakhov , E. Lanina , A. Morozov

For strongly invertible knots, we define an involutive version of Khovanov homology, and from it derive a pair of integer-valued invariants $(\underline{s}, \bar{s})$, which is an equivariant version of Rasmussen's $s$-invariant. Using…

Geometric Topology · Mathematics 2025-11-26 Taketo Sano

Given a diagram D of a knot K, we give easily computable bounds for Rasmussen's concordance invariant s(K). The bounds are not independent of the diagram D chosen, but we show that for diagrams satisfying a given condition the bounds are…

Geometric Topology · Mathematics 2012-12-12 Andrew Lobb

We use deep neural networks to machine learn correlations between knot invariants in various dimensions. The three-dimensional invariant of interest is the Jones polynomial $J(q)$, and the four-dimensional invariants are the Khovanov…

High Energy Physics - Theory · Physics 2023-02-22 Jessica Craven , Mark Hughes , Vishnu Jejjala , Arjun Kar

The main goal of the present paper is to construct new invariants of knots with additional structure by adding new gradings to the Khovanov complex. The ideas given below work in the case of virtual knots, closed braids and some other cases…

Geometric Topology · Mathematics 2007-10-22 Vassily Olegovich Manturov

In this paper we reconsider the original Kolmogorov normal form algorithm with a variation on the handling of the frequencies. At difference with respect to the Kolmogorov approach, we do not keep the frequencies fixed along the…

Dynamical Systems · Mathematics 2023-04-05 Marco Sansottera , Veronica Danesi

Skew polynomials are a class of non-commutative polynomials that have several applications in computer science, coding theory and cryptography. In particular, skew polynomials can be used to construct and decode evaluation codes in several…

Information Theory · Computer Science 2022-07-05 Hannes Bartz , Thomas Jerkovits , Johan Rosenkilde

We construct an algebra of non-trivial homological operations on Khovanov homology with coefficients in $\mathbb Z_2$ generated by two Bockstein operations. We use the unified Khovanov homology theory developed by the first author to lift…

Algebraic Topology · Mathematics 2016-01-06 Krzysztof K. Putyra , Alexander N. Shumakovitch

We introduce an invariant of tangles in Khovanov homology by considering a natural inverse system of Khovanov homology groups. As application, we derive an invariant of strongly invertible knots; this invariant takes the form of a graded…

Geometric Topology · Mathematics 2017-04-07 Liam Watson

There exists a simplified Bar-Natan Khovanov complex for open 2-braids. The Khovanov cohomology of a knot diagram made by gluing tangles of this type is therefore often amenable to calculation. We lift this idea to the level of the…

Geometric Topology · Mathematics 2015-06-26 Dan Jones , Andrew Lobb , Dirk Schuetz