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Related papers: Rack shadows and their invariants

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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 $ns^at^a$-quandles are not classified by their generalized quandle…

Geometric Topology · Mathematics 2019-03-13 Tim Carrell , Sam Nelson

We demonstrate that there is a large class of compact metric spaces for which the shadowing property can be characterized as a structural property of the space of dynamical systems. We also demonstrate for this class of spaces, that in…

Dynamical Systems · Mathematics 2021-06-30 Jonathan Meddaugh

The notion of a pseudoknot is defined as an equivalence class of knot diagrams that may be missing some crossing information. We provide here a topological invariant schema for pseudoknots and their relatives, 4-valent rigid vertex spatial…

Geometric Topology · Mathematics 2016-03-15 Allison Henrich , Louis H. Kauffman

We define a new algebraic structure called Legendrian racks or racks with Legendrian structure, motivated by the front-projection Reidemeister moves for Legendrian knots. We provide examples of Legendrian racks and use these algebraic…

Geometric Topology · Mathematics 2021-01-26 Jose Ceniceros , Mohamed Elhamdadi , Sam Nelson

The definition of edge-regularity in graphs is a relaxation of the definition of strong regularity, so strongly regular graphs are edge-regular and, not surprisingly, the family of edge-regular graphs is much larger and more diverse than…

Combinatorics · Mathematics 2025-04-14 Jared DeLeo

A shadow of a geometric object $A$ in a given direction $v$ is the orthogonal projection of $A$ on the hyperplane orthogonal to $v$. We show that any topological embedding of a circle into Euclidean $d$-space can have at most two shadows…

Metric Geometry · Mathematics 2017-06-09 Michael Gene Dobbins , Heuna Kim , Luis Montejano , Edgardo Roldán-Pensado

Biquandle brackets are a type of quantum enhancement of the biquandle counting invariant for oriented knots and links, defined by a set of skein relations with coefficients which are functions of biquandle colors at a crossing. In this…

Geometric Topology · Mathematics 2019-09-04 Neslihan Gügümcü , Sam Nelson , Natsumi Oyamaguchi

A system of linear equations over a skew field has properties similar to properties of a system of linear equations over a field. Even noncommutativity of a product creates a new picture the properties of system of linear equations and of…

Rings and Algebras · Mathematics 2010-07-19 Aleks Kleyn

Marked vertex diagrams provide a combinatorial way to represent knotted surfaces in $\mathbb{R}^4$; including virtual crossings allows for a theory of virtual knotted surfaces and virtual cobordisms. Biquandle counting invariants are…

Geometric Topology · Mathematics 2015-06-08 Sam Nelson , Patricia Rivera

Classical shadows are a computationally efficient approach to storing quantum states on a classical computer for the purposes of estimating expectation values of local observables, obtained by performing repeated random measurements. In…

Quantum Physics · Physics 2023-05-03 Saumya Shivam , C. W. von Keyserlingk , S. L. Sondhi

Differentiable rendering has received increasing interest for image-based inverse problems. It can benefit traditional optimization-based solutions to inverse problems, but also allows for self-supervision of learning-based approaches for…

Computer Vision and Pattern Recognition · Computer Science 2021-04-02 Linjie Lyu , Marc Habermann , Lingjie Liu , Mallikarjun B R , Ayush Tewari , Christian Theobalt

We introduce an algebra Z[X,S] associated to a pair (X,S) of a virtual birack X and X-shadow S. We use modules over Z[X,S] to define enhancements of the virtual birack shadow counting invariant, extending the birack shadow module invariants…

Geometric Topology · Mathematics 2012-04-20 Jackson Blankstein , Susan Kim , Catherine Lepel , Sam Nelson , Nicole Sanderson

The involutory birack counting invariant is an integer-valued invariant of unoriented tangles defined by counting homomorphisms from the fundamental involutory birack of the tangle to a finite involutory birack over a set of framings modulo…

Geometric Topology · Mathematics 2014-03-18 Sam Nelson , Veronica Rivera

In this article, we introduce rack invariants of oriented Legendrian knots in the 3-dimensional Euclidean space endowed with the standard contact structure, which we call Legendrian racks. These invariants form a generalization of the…

Geometric Topology · Mathematics 2017-07-04 Dheeraj Kulkarni , T. V. H. Prathamesh

We define the fundamental quandle of a spatial graph and several invariants derived from it. In the category of graph tangles, we define an invariant based on the walks in the graph and cocycles from nonabelian quandle cohomology.

Geometric Topology · Mathematics 2019-10-29 Maciej Niebrzydowski

We address various notions of shadowing and expansivity for continuous maps restricted to a proper subset of their domain. We prove new equivalences of shadowing and expansive properties, we demonstrate under what conditions certain…

Dynamical Systems · Mathematics 2015-05-20 Andrew Barwell , Chris Good , Piotr Oprocha

In this note we compute some enumerative invariants of real and complex projective spaces by means of some enriched graphs called floor diagrams.

Algebraic Geometry · Mathematics 2007-06-04 Erwan Brugallé , Grigory Mikhalkin

In this short survey article we collect the current state of the art in the nascent field of \textit{quantum enhancements}, a type of knot invariant defined by collecting values of quantum invariants of knots with colorings by various…

Geometric Topology · Mathematics 2026-02-19 Sam Nelson

We characterize which graph invariants are partition functions of an edge-coloring model over the complex numbers, in terms of the rank growth of associated `connection matrices'.

Combinatorics · Mathematics 2015-06-25 Alexander Schrijver

In order to construct a representation of the tangle category one needs an enhanced R-matrix. In this paper we define a sufficient and necessary condition for enhancement that can be checked easily for any R-matrix. If the R-matrix can be…

q-alg · Mathematics 2008-02-03 Marco Arien Mackaay