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A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

168,695 papers · 148 categories

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48 results for special alternating links

Study sharpens unlinking number bounds for special alternating links.

problem Determining the exact unlinking number for special alternating links.
method Analyzes links in the 3-sphere, focusing on special alternating links and their crossing changes.
result Sharp lower bounds for unlinking number realized by crossing changes in alternating diagrams.

Study Alexander polynomials of special alternating links and generalize Fox's conjecture.

problem Distinguish special alternating links up to isotopy using polynomial invariants.
method Combinatorial and discrete geometric properties of Alexander polynomials of special alternating links.
result Generalized Alexander polynomials of special alternating links can be expressed in terms of volumes of root polytopes of unimodular matrices.

We solve a century-old conjecture about Alexander polynomials of special alternating links.

problem Fox's conjecture about unimodality of Alexander polynomial coefficients.
method Proving a multivariate generalization of the Alexander polynomial is Lorentzian.
result Alexander polynomial coefficients of special alternating links form a log-concave sequence.

New proof of trapezoidal property for Alexander polynomials of special alternating links.

problem Proving trapezoidal property of Alexander polynomials for special alternating links.
method Analyzing vector configurations from matroids and totally positive matrices.
result Alexander polynomials of special alternating links exhibit log-concavity and trapezoidal properties.

Given a prime, alternating link diagram, we build a special cover of the link complement whose degree is bounded by a factorial function of the crossing number. It follows that a subgroup of the link group of that index embeds into right-angled Artin and Coxeter groups. Corollaries of this result include a quantificati…

2019-09-26abs ↗pdf ↗

We establish a characterization of alternating links in terms of definite spanning surfaces. We apply it to obtain a new proof of Tait's conjecture that reduced alternating diagrams of the same link have the same crossing number and writhe. We also deduce a result of Banks and Hirasawa-Sakuma about Seifert surfaces for…

2015-11-19abs ↗pdf ↗

This paper computes Kakimizu complexes for all 11 crossing prime alternating knots.

problem Computing Kakimizu complexes for prime, alternating knots with 11 crossings.
method Used known algorithms and Murasugi sums with sutured manifold theory.
result Explicitly described Kakimizu complexes for all 11 crossing prime alternating knots.

By applying Seifert's algorithm to a special alternating diagram of a link L, one obtains a Seifert surface F of L. We show that the support of the sutured Floer homology of the sutured manifold complementary to F is affine isomorphic to the set of lattice points given as hypertrees in a certain hypergraph that is natu…

2011-12-12abs ↗pdf ↗

The Jones polynomial of an alternating link is a certain specialization of the Tutte polynomial of the (planar) checkerboard graph associated to an alternating projection of the link. The Bollobas-Riordan-Tutte polynomial generalizes the Tutte polynomial of planar graphs to graphs that are embedded in closed oriented s…

2006-05-21abs ↗pdf ↗

We give a topological characterisation of alternating knot exteriors based on the presence of special spanning surfaces. This shows that alternating is a topological property of the knot exterior and not just a property of diagrams, answering an old question of Fox. We also give a characterisation of alternating link e…

2015-11-16abs ↗pdf ↗

In this thesis we work with Khovanov homology of links and its generalizations, as well as with the homology of graphs. Khovanov homology of links consists of graded chain complexes which are link invariants, up to chain homotopy, with graded Euler characteristic equal to the Jones polynomial of the link. Hence, it can…

2006-05-22abs ↗pdf ↗

It is known that the minimal degree of the Jones polynomial of a positive knot is equal to its genus, and the minimal coefficient is 1. We extend this result to almost positive links and partly identify the 3 following coefficients for special types of positive links. We also give counterexamples to the Jones polynomia…

2002-02-22abs ↗pdf ↗

Nahm sums are qq-series of a special hypergeometric type that appear in character formulas in Conformal Field Theory, and give rise to elements of the Bloch group, and have interesting modularity properties. In our paper, we show how Nahm sums arise naturally in Quantum Knot Theory, namely we prove the stability of th…

2011-12-16abs ↗pdf ↗

For each graph and each positive integer nn, we define a chain complex whose graded Euler characteristic is equal to an appropriate nn-specialization of the dichromatic polynomial. This also gives a categorification of nn-specializations of the Tutte polynomial of graphs. Also, for each graph and integer n2n\le 2, w…

2005-04-12abs ↗pdf ↗

It is well known that any link can be represented by the closure of a braid. The minimum number of strings needed in a braid whose closure represents a given link is called the braid index of the link and the well known Morton-Frank-Williams inequality reveals a close relationship between the HOMFLY polynomial of a lin…

2016-04-20abs ↗pdf ↗

New quasi-alternating links created from existing ones.

problem Creating new quasi-alternating links from existing ones.
method Extending the construction of quasi-alternating links by replacing a crossing with an alternating tangle of the same type.
result Jones polynomial of new quasi-alternating links has no gap if the original link has no gap.

We show that the volumes of certain hyperbolic A-adequate links can be bounded (above and) below in terms of two diagrammatic quantities: the twist number and the number of certain alternating tangles in an A-adequate diagram. We then restrict our attention to plat closures of certain braids, a rich family of links who…

2013-10-31abs ↗pdf ↗

Extends classical results to virtual links, proving new properties of alternating and semi-alternating virtual links.

problem Classical results for virtual links, focusing on alternating and semi-alternating links.
method Inequality relating link determinant and crossing number, matrix-tree theorem, Tait conjectures for virtual and welded links.
result Alexander polynomial of almost classical alternating virtual links is alternating.

Study of alternating links on nonorientable surfaces, extending results to nonorientable projections.

problem Generalizing hyperbolic geometry results to nonorientable surfaces.
method Extending results from orientable to nonorientable surfaces.
result Klein-bottly alternating links in prism manifolds have hyperbolic geometry.

We construct an infinite family of quasi-alternating links from a given quasi-alternating link by replacing a crossing by a product of rational tangles each of which extends that crossing. Consequently, we determine an infinite family of quasi-alternating Montesinos links. This family contains all the classes of quasi-…

2012-05-21abs ↗pdf ↗

We prove that twisting any quasi-alternating link LL with no gaps in its Jones polynomial VL(t)V_L(t) at the crossing where it is quasi-alternating produces a link LL^{*} with no gaps in its Jones polynomial VL(t)V_{L^*}(t). This leads us to conjecture that the Jones polynomial of any prime quasi-alternating link, other th…

2018-10-28abs ↗pdf ↗

Quasi-alternating links are homologically thin for both Khovanov homology and knot Floer homology. We show that every quasi-alternating link gives rise to an infinite family of quasi-alternating links obtained by replacing a crossing with an alternating rational tangle. Consequently, we show that many pretzel links are…

2007-12-16abs ↗pdf ↗

New invariants derived from Seifert graphs help distinguish alternating links.

problem Distinguishing alternating links from each other.
method Introducing new quantities derived from Seifert graphs of reduced alternating link diagrams and proving they are link invariants.
result These new invariants can easily distinguish many different alternating links, even large and complicated ones.

Meridian lemma extended to fully alternating links in thickened surfaces.

problem Extending Menasco's meridian lemma to fully alternating links in thickened surfaces.
method Developed a new meridian lemma for fully alternating links in thickened orientable surfaces of positive genus.
result The meridian lemma holds for fully alternating links in thickened surfaces.

An alternating distance is a link invariant that measures how far away a link is from alternating. We study several alternating distances and demonstrate that there exist families of links for which the difference between certain alternating distances is arbitrarily large. We also show that two alternating distances, t…

2014-06-26abs ↗pdf ↗

The aim of this article is to detect new classes of quasi-alternating links. Quasi-alternating links are a natural generalization of alternating links. Their knot Floer and Khovanov homology are particularly easy to compute. Since knot Floer homology detects the genus of a knot as well as whether a knot is fibered, as …

2008-11-03abs ↗pdf ↗

A link is almost alternating if it is non-alternating and has a diagram that can be transformed into an alternating diagram via one crossing change. We give formulas for the first two and last two potential coefficients of the Jones polynomial of an almost alternating link. Using these formulas, we show that the Jones …

2017-07-18abs ↗pdf ↗

The purpose of this article is to give a preliminary clarification on the relation between crossing number and crossing change. With a main focus on the span of X polynomial, we prove that, as our theorem claims, the crossing number of the link after crossing change can be estimated when certain conditions are met. At …

2011-03-24abs ↗pdf ↗

New findings on hyperbolicity of augmented links in thickened surfaces.

problem Proving hyperbolicity of links in thickened surfaces.
method Extending hyperbolicity results to generalized augmented cellular alternating links.
result Generalized augmented cellular alternating links in thickened surfaces are hyperbolic.

Standard position for surfaces extended to weakly generalized alternating links.

problem Proving standard position for surfaces in a broader class of links.
method Extending techniques from classical alternating links to weakly generalized alternating links.
result All weakly generalized alternating links are prime, and Conway spheres interact with diagrams as in classical setting.

In this paper, we show that a link which has a positive and almost alternating diagram is alternating, besides that a positive and non-alternating Montesinos link has an almost positive-alternating diagram.

2015-10-12abs ↗pdf ↗