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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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7152229 · May 202219922001200920172026
48 results for braid diagram

The notion of a braided chord diagram is introduced and studied. An equivalence relation is given which identifies all braidings of a fixed chord diagram. It is shown that finite-type invariants are stratified by braid index for knots which can be represented as closed 3-braids. Partial results are obtained about spann…

1998-04-03abs ↗pdf ↗

New procedures connect braid charts, triplane diagrams, and braid movies for knotted surfaces.

problem Understanding the braid index and bridge index of knotted surfaces in 4D.
method Introducing rainbow diagrams and new procedures for passing among triplane diagrams, braid movies, and braid charts.
result Inequalities relating braid index and bridge index of 2-knots are obtained.

Virtual braids are a combinatorial generalization of braids. We present abstract braids as equivalence classes of braid diagrams on a surface, joining two distinguished boundary components. They are identified up to isotopy, compatibility, stability and Reidemeister moves. We show that virtual braids are in a bijective…

2014-02-03abs ↗pdf ↗

This paper introduces cluster exchange groupoids for Coxeter-Dynkin diagrams and finds their fundamental groups are braid groups.

problem Understanding the fundamental groups of cluster exchange groupoids for Coxeter-Dynkin diagrams.
method Introduced cluster exchange groupoids for Coxeter-Dynkin diagrams and showed the fundamental group isomorphic to braid groups.
result The fundamental group of the exchange groupoid for a Coxeter-Dynkin diagram is the braid group associated with the diagram.

A knot (or link) diagram is said to be everywhere equivalent if all the diagrams obtained by switching one crossing represent the same knot (or link). We classify such diagrams of a closed 3-braid.

2014-11-16abs ↗pdf ↗

Braids can be represented geometrically as curve diagrams. The geometric complexity of a braid is the minimal complexity of a curve diagram representing it. We introduce and study the corresponding notion of geometric generating function. We compute explicitly the geometric generating function for the group of braids o…

2015-03-02abs ↗pdf ↗

Given a knot diagram DD, we construct a semi-threading circle for it which can be an axis of DD as a closed braid depending on knot diagrams. In particular, we consider semi-threading circles for minimal diagrams of a knot with respect to overpasses which give us some information related to the braid index. By this n…

2013-02-15abs ↗pdf ↗

We show that every trivial 3-strand braid diagram contains a disk, defined as a ribbon ending in opposed crossings. Under a convenient algebraic form, the result extends to every Artin--Tits group of dihedral type, but it fails to extend to braids with 4 strands and more. The proof uses a partition of the Cayley graph …

2003-11-19abs ↗pdf ↗

New groups from strand diagrams show polycyclic subgroups are virtually abelian and undistorted.

problem Understanding the structure of mapping class groups.
method Introducing Chambord groups from braided strand diagrams and semigroup presentations.
result Polycyclic subgroups in Chambord groups are virtually abelian and undistorted.

A crossing in a knot is nugatory if changing the crossing does not change the knot type. Using an invariant of certain types of closed 3-braid diagrams, we show that if a closed 3-braid contains a nugatory crossing then its braid index is one or two. This proves a special case of a conjecture on nugatory crossings due …

2010-01-10abs ↗pdf ↗

Laundry surfaces for closed braid diagrams are presented. It is shown that braid diagrams are characterized by linking matrices obtained by lifting cycles from these surfaces. Oriented link types are then characterized by equivalence classes of linking matrices. Similar equivalence classes can be composed of Gordon and…

2006-09-05abs ↗pdf ↗

The paper describes handle decompositions and Kirby diagrams for plane algebraic curves.

problem Understanding the topology of the complement of plane algebraic curves.
method Using braid monodromy to refine handle decompositions and Kirby diagrams.
result Explicit handle decompositions and Kirby diagrams for plane algebraic curves are provided.

We prove new results about unknotting fibered positive knots and braids.

problem Proving the unknotting number equals genus for fibered positive knots and braids.
method Analyzing positive braid diagrams and fibered positive knots, proving new constraints and conjectures.
result We found fibered positive knots that cannot be unknotted optimally, contradicting Stoimenow's conjecture.

Study improves HOMFLY polynomial coefficients for positive braid links.

problem Determining HOMFLY polynomial coefficients for positive braid links.
method Using geometric invariants like maximum Euler characteristics, number of split and prime factors.
result Improvements in known results for Conway and Jones polynomials of positive braid links.

We describe a new method for combinatorially computing the transverse invariant in knot Floer homology. Previous work of the authors and Stone used braid diagrams to combinatorially compute knot Floer homology of braid closures. However, that approach was unable to explicitly identify the invariant of transverse links …

2017-03-20abs ↗pdf ↗

Let β:=σ1σ21β:=σ_1σ_2^{-1} be a braid in B3B_3, where B3B_3 is the braid group on 3 strings and σ1,σ2σ_1, σ_2 are the standard Artin generators. We use Gauss diagram formulas to show that for each natural number nn not divisible by 33 the knot which is represented by the closure of the braid βnβ^n is algebraically slice if an…

2016-04-14abs ↗pdf ↗

Study of spaces of pure braids and string links using diagrams and integrals.

problem Understanding spaces of pure braids and string links through algebraic structures.
method Use of Kontsevich's CDGA of diagrams and Chen's iterated integrals to establish Hopf algebra isomorphisms and connections.
result Established a correspondence between Milnor invariants and Chen integrals for Brunnian spherical links.

In previous papers, the author realized the following principle for many knot theories: if a knot diagram is complicated enough then it reproduces itself, i.e., is a subdiagram of any other diagram equivalent to it. This principle is realized by diagram-valued invariants [ ] of knots such that [K]=K. It turns out that …

2015-01-03abs ↗pdf ↗

Two virtual link diagrams are homotopic if one may be transformed into the other by a sequence of virtual Reidemeister moves, classical Reidemeister moves, and self crossing changes. We recall the pure virtual braid group. We then describe the set of pure virtual braids that are homotopic to the identity braid.

2007-04-23abs ↗pdf ↗

We present a braid-theoretic approach to combinatorially computing knot Floer homology. To a knot or link K, which is braided about the standard disk open book decomposition for (S^3,ξ_std), we associate a corresponding multi-pointed nice Heegaard diagram. We then describe an explicit algorithm for computing the associ…

2013-12-19abs ↗pdf ↗

We show that Vassiliev invariants separate braids on a closed oriented surface, and we exhibit an universal Vassiliev invariant for these braids in terms of chord diagrams labeled by elements of the fundamental group of the considered surface.

2000-06-02abs ↗pdf ↗

We characterise positive braid links with positive Seifert form via a finite number of forbidden minors. From this we deduce a one-to-one correspondence between prime positive braid links with positive Seifert form and simply laced Dynkin diagrams, as well as a simple classification of alternating positive braid knots.

2012-11-20abs ↗pdf ↗

In this paper, we show that the volumes for a family of A-adequate closed braids can be bounded above and below in terms of the twist number, the number of braid strings, and a quantity that can be read from the combinatorics of a given closed braid diagram. We also show that the volumes for many of these closed braids…

2014-06-28abs ↗pdf ↗

A Gauss diagram is a simple, combinatorial way to present a link. It is known that any Vassiliev invariant may be obtained from a Gauss diagram formula that involves counting subdiagrams of certain combinatorial types. In this paper we present simple formulas for an infinite family of invariants in terms of counting su…

2012-09-06abs ↗pdf ↗

We generalize bridge trisections to surfaces in four-manifolds, linking them to braided links.

problem Embedding surfaces in four-manifolds and understanding their braiding.
method Introducing bridge trisections, isotoping surfaces, and using trisections and open-book decompositions.
result Any neatly embedded surface can be isotoped to lie in bridge trisection position with respect to any trisection of the four-manifold.

The Magnus expansion is a universal finite type invariant of pure braids with values in the space of horizontal chord diagrams. The Conway polynomial composed with the short circuit map from braids to knots gives rise to a series of finite type invariants of pure braids and thus factors through the Magnus map. We descr…

2010-01-14abs ↗pdf ↗

In the first half of the paper we construct a Morse-type theory on certain spaces of braid diagrams. We define a topological invariant of closed positive braids which is correlated with the existence of invariant sets of parabolic flows defined on discretized braid spaces. Parabolic flows, a type of one-dimensional lat…

2001-05-10abs ↗pdf ↗

We define the braid groups of a two-dimensional orbifold and introduce conventions for drawing braid pictures. We use these to realize the Artin groups associated to the spherical Coxeter diagrams A_n, B_n=C_n and D_n and the affine diagrams tilde{A}_n, tilde{B}_n, tilde{C}_n and tilde{D}_n as subgroups of the braid gr…

1999-07-30abs ↗pdf ↗

In this paper, we define the set of singular grid diagrams SG\mathcal{SG} which provides a unified description for singular links, singular Legendrian links, singular transverse links, and singular braids. We also classify the complete set of all equivalence relations on SG\mathcal{SG} which induce the bijection onto e…

2017-08-12abs ↗pdf ↗