Study rack invariants for links in lens space L(p,1).
problem Applying classical rack invariants to links in L(p,1). method Presented augmented fundamental rack, applied counting rack invariants, included information about π1(L(p,1)) action. result Counting rack invariants provide information about π1(L(p,1)) action on links in L(p,1). Defines fundamental racks for braid spaces of complex reflection groups.
problem Understanding fundamental racks for braid spaces of complex reflection groups.
method Defines an augmented rack associated to the orbifold fundamental group.
result Yields representations of the orbifold fundamental group on the cohomology of the rack space.
Paper proves Legendrian knots with same GL-rack have similar invariants.
problem Classifying Legendrian knots based on their invariants.
method Examined fundamental GL-racks and their relationship to Thurston-Bennequin and rotation numbers.
result Two Legendrian knots with isomorphic fundamental GL-racks have similar invariants.
This paper extends rack and quandle covering theory using higher categorical Galois theory.
problem Developing a higher covering theory of racks and quandles.
method Applying techniques from higher categorical Galois theory to extend and clarify the foundations of rack and quandle coverings.
result Identification of meaningful higher-dimensional centrality conditions defining higher coverings of racks and quandles.
Study reveals new structures in knot theory categories.
problem Understanding the center and power operations in rack and quandle categories.
method Developed categorical aspects, computed centers, and described power operations.
result Revealed free extra structure not apparent from definitions.
New rack and multiple group rack cohomology for surfaces in 3-sphere.
problem Categorizing compact oriented surfaces in 3-sphere based on symmetry.
method Developed cohomology theory for racks and multiple group racks, constructed cocycle invariants.
result Identified new symmetry types of surfaces in 3-sphere.
Study of generalized Legendrian racks and their GL-structures.
problem Characterizing and classifying generalized Legendrian racks.
method Algebraic analysis, classification of racks and GL-racks, tensor products.
result Classification of several infinite families of GL-racks.
New racks defined; properties of rack representations explored.
problem Characterizing and studying rack representations.
method Definition of finitely stable racks, characterization of Alexander quandles, study of twisted rack dynamical systems, construction of cross-products, representation theory of racks and quandles.
result Definition and properties of Pontryagin dual of racks.
New method constructs multiple group racks, differing from known constructions.
problem Define new invariants for spatial surfaces.
method Using a G-family of racks and a normal subgroup N of G.
result New method yields multiple group racks not derived from known methods.
A rack of order n is a binary operation $\rack$ on a set X of cardinality n, such that right multiplication is an automorphism. More precisely, $(X,\rack)$ is a rack provided that the map $x\mapsto x\rack y$ is a bijection for all y∈X, and $(x\rack y)\rack z=(x\rack z)\rack (y\rack z)$ for all x,y,z∈X. …
The paper connects GL-racks to knot coloring invariants.
problem Understanding invariants of Legendrian knots.
method Exploring GL-racks and their decomposition into permutation and block GL-racks.
result Equivalent coloring invariants for knots with identical classical invariants.
We give a foundational account on topological racks and quandles. Specifically, we define the notions of ideals, kernels, units, and inner automorphism group in the context of topological racks. Further, we investigate topological rack modules and principal rack bundles. Central extensions of topological racks are then…
Innovative rack theory applied to Legendrian links.
problem Classifying and distinguishing Legendrian links.
method Purely rack-theoretic approach, Legendrian Reidemeister moves, cusps, homogeneous representations, modules.
result Invariant distinguishes infinitely many Legendrian unknots and trefoils.
This paper characterizes extensions of augmented racks and constructs invariants for surfaces.
problem Characterizing extensions of augmented racks and constructing invariants for surfaces.
method Characterization of rack extensions through fibrant and additive cohomology, construction of invariants using cocycles.
result Characterization of extensions of augmented racks and construction of surface invariants.
We study Coxeter racks over Zn and the knot and link invariants they define. We exploit the module structure of these racks to enhance the rack counting invariants and give examples showing that these enhanced invariants are stronger than the unenhanced rack counting invariants.
The paper integrates Lie-Leibniz triples into Lie group-rack triples.
problem Integrating Lie-Leibniz triples into Lie group structures.
method Defining Lie group-rack triples and integrating finite-dimensional Lie-Leibniz triples.
result Any finite-dimensional Lie-Leibniz triple can be integrated to a local Lie group-rack triple.
4-Legendrian permutation racks can't distinguish knots but recover classical invariants.
problem Distinguishing Legendrian knots using permutation racks.
method Study of 4-Legendrian racks and their effectiveness.
result 4-Legendrian permutation racks cannot distinguish knots but recover classical invariants.
A rack shadow is a set X with a rack action by a rack R, analogous to a vector space over a field. We use shadow colorings of classical link diagrams to define enhanced rack counting invariants and show that the enhanced invariants are stronger than unenhanced counting invariants.
The theory of rack and quandle modules is developed - in particular a tensor product is defined, and shown to satisfy an appropriate adjointness condition. Notions of free rack and quandle modules are introduced, and used to define an enveloping object (the `rack algebra' or `wring') for a given rack or quandle. These …
Racks do not give us invariants of surface-knots in general. For example, if a surface-knot diagram has branch points (and a rack which we use satisfies some mild condition), then it admits no rack colorings. In this paper, we investigate rack colorings for surface-knot diagrams without branch points and prove that rac…
We introduce a modified rack algebra Z[X] for racks X with finite rack rank N. We use representations of Z[X] into rings, known as rack modules, to define enhancements of the rack counting invariant for classical and virtual knots and links. We provide computations and examples to show that the new invariants are stric…
We study rack polynomials and the link invariants they define. We show that constant action racks are classified by their generalized rack polynomials and show that nsata-quandles are not classified by their generalized quandle polynomials. We use subrack polynomials to define enhanced rack counting invariants, gen…
A (t,s)-rack is a rack structure defined on a module over the ring Λ¨=Z[t±1,s]/(s2−(1−t)s). We identify necessary and sufficient conditions for two (t,s)-racks to be isomorphic. We define enhancements of the rack counting invariant using the structure of (t,s)-racks and give some computations an…
The paper introduces a new coloring invariant for spatial surfaces using a multiple group rack.
problem Distinguishing spatial surfaces embedded in the 3-sphere.
method Defined a coloring invariant using a multiple group rack.
result Introduced a new invariant to distinguish spatial surfaces.
New algebraic structures help distinguish Legendrian knots.
problem Distinguishing Legendrian knots from smooth knots.
method Defined Legendrian racks and used them to define invariants.
result Distinguished certain Legendrian knots.
New algebraic structure helps distinguish braids.
problem Distinguishing braids using mathematical invariants.
method Defined pointed racks and used them to create braiding invariants.
result New invariants can distinguish braids not previously possible.
This paper develops graph theory for racks and quasigroups.
problem Characterizing and realizing right quasigroups and related structures.
method Study of graph markings, Schreier graphs, and Cayley graphs.
result All right quasigroups are realizable by specific types of graphs.
We define ambient isotopy invariants of oriented knots and links using the counting invariants of framed links defined by finite racks. These invariants reduce to the usual quandle counting invariant when the rack in question is a quandle. We are able to further enhance these counting invariants with 2-cocycles from th…
Survey of recent developments in racks and quandles.
problem Understanding recent advancements in algebraic theory of racks and quandles.
method Report on representation theory of quandles and ring theoretic approach.
result Presentation of recent elements in quandle theory.
New rack invariants detect geometric properties of Legendrian knots.
problem Detecting geometric properties of Legendrian knots.
method Introducing Legendrian racks, a generalization of quandle invariants.
result These invariants form a natural generalization of quandle invariants.
Classifies good involutions in conjugation subquandles and racks.
problem Classifying quandles with good involutions for applications in surface-knot theory.
method Study of subquandles of conjugation quandles, including core quandles; analysis of good involutions of faithful racks.
result Sharp bounds on the number of good involutions of racks in these families.
The paper constructs Yang-Baxter solutions using categorical augmented racks.
problem Solutions to the Yang-Baxter equation in knot theory.
method Interpreting augmented racks in tensor categories and constructing solutions using quantum heaps and Hopf algebra modules.
result Explicit constructions and infinite families of Yang-Baxter solutions are provided.
The paper computes rack homology for a specific family of quandles.
problem Computing rack homology for graphic quandles.
method Review of rack homology, computation of second rack homology groups for graphic quandles.
result Computed second rack homology groups for a large family of graphic quandles.
Study homotopy types of free racks and quandles, proving analogs of Milnor's theorem.
problem Understanding the homotopy types of free racks and quandles.
method Proved analogs of Milnor's theorem for racks and quandles and their pointed variants.
result Identified the homotopy types of free racks and quandles on spaces of generators.
New method to calculate 3-manifold invariants via skew-racks.
problem Calculating invariants of 3-manifolds.
method Introducing skew-racks with good involution and Property FR, defining cocycle invariants.
result Established new approach to obtain 3-manifold invariants via Dehn surgery.
The study enumerates virtual quandles up to isomorphism.
problem Classifying virtual quandles up to isomorphism.
method Computer search and classification based on conjugacy class structures of rack automorphism groups.
result Classifications of virtual racks and quandles up to order 8.
We show that the lower bounds for Betti numbers given in math.GT/9909161 are equalities for a class of racks that includes dihedral and Alexander racks. We confirm a conjecture from the same paper by defining a splitting for the short exact sequence of quandle chain complexes. We define isomorphisms between Alexander r…
The homology and cohomology of quandles and racks are used in knot theory: given a finite quandle and a cocycle, we can construct a knot invariant. This is a quick introductory survey to the invariants of knots derived from quandles and racks.
A process enumerates rack elements from a presentation.
problem Systematically enumerating elements of racks from presentations.
method Generalizes Todd-Coxeter process for cosets, adapted for racks.
result Process terminates if and only if rack is finite, outputting operation tables.
The aim of this paper is to define a homology theory for racks with finite rank N and use it to define invariants of knots generalizing the CJKLS 2-cocycle invariants related to the invariants defined in [15]. For this purpose, we prove that N -degenerate chains form a sub-complex of the classical complex defining rack…
The paper introduces groupoid racks for spatial surfaces.
problem Coloring diagrams of spatial surfaces for invariant calculation.
method Introduces groupoid racks with universal properties.
result Groupoid racks provide an invariant for spatial surfaces.
Proposes a new notation for biracks to simplify rack structure analysis.
problem Simplifying birack notation for easier rack structure analysis.
method Introduces a new notation that includes rack structure knowledge from the start.
result Generalizes results from involutive to non-involutive biracks and clarifies rack structure relations.
Analytic Lie rack structures on Leibniz algebras are characterized and rigid Lie algebras are identified.
problem Characterizing and identifying rigid Lie algebras with analytic Lie rack structures.
method Analytic Lie rack structures are defined and characterized using multilinear equations and cohomological interpretations.
result Simple Lie algebras are conjectured to be rigid as left Leibniz algebras.
We introduce the notion of N-reduced dynamical cocycles and use these objects to define enhancements of the rack counting invariant for classical and virtual knots and links. We provide examples to show that the new invariants are not determined by the rack counting invariant, the Jones polynomial or the generalized Al…
Second part of a series on higher coverings of racks and quandles.
problem Characterizing higher-dimensional centrality conditions in racks and quandles.
method Applying higher categorical Galois theory to racks and quandles.
result Identification and characterization of higher coverings, trivial coverings, and normal coverings.
New definitions of rack and quandle modules are introduced, and shown to generalise the definitions previously studied by Andruskiewitsch, Etingof and Grana. This new construct is shown to coincide with Beck's general definition of a module in an arbitrary category. A theory of Abelian extensions of racks and quandles …
In this paper we describe methods for computing rack and quandle cohomology. We illustrate these methods by completely determining the cohomology of prime dihedral quandles.
Heap theory applied to framed links yields new invariants.
problem Developing invariants for framed links using heap theory.
method Introducing fundamental heap, defining cocycle invariant using ternary cohomology.
result Found cocycles and computed invariants for specific link families.