English
Related papers

Related papers: Note on spherical quandles

200 papers

We introduce a unified framework for counting representations of knot groups into $SU(2)$ and $SL(2, \mathbb{R})$. For a knot $K$ in the 3-sphere, Lin and others showed that a Casson-style count of $SU(2)$ representations with fixed…

Geometric Topology · Mathematics 2025-12-03 Nathan M. Dunfield , Jacob Rasmussen

The knot coloring polynomial defined by Eisermann for a finite pointed group is generalized to an infinite pointed group as the longitudinal mapping invariant of a knot. In turn this can be thought of as a generalization of the quandle…

Geometric Topology · Mathematics 2018-02-27 W. Edwin Clark , Masahico Saito

The fundamental quandle is a complete invariant for unoriented tame knots \cite{JO, Ma} and non-split links \cite{FR}. The proof involves proving a relationship between the components of the fundamental quandle and the cosets of the…

Geometric Topology · Mathematics 2026-02-26 Blake Mellor

We define an integer valued invariant for two-component links in S^3 by counting projective SU(2) representations of the link group having non-trivial second Stiefel-Whitney class. We show that our invariant is, up to sign, the linking…

Geometric Topology · Mathematics 2009-11-23 Eric Harper , Nikolai Saveliev

Given a 2-stranded tangle in a $\ZZ/2$ homology ball, $T\subset Y$, we investigate the character variety $R(Y,T)$ of conjugacy classes of traceless SU(2) representations of $\pi_1(Y\setminus T)$. In particular we completely determine the…

Geometric Topology · Mathematics 2016-06-08 Yoshihiro Fukumoto , Paul Kirk , Juanita Pinzón-Caicedo

Coloring numbers are one of the simplest combinatorial invariants of knots and links to describe. And with Joyce's introduction of quandles, we can understand them more algebraically. But can we extend these invariants to tangles -- knots…

Geometric Topology · Mathematics 2008-03-12 John Armstrong

The knot quandle is an invariant of $n$-knots. In this note, we study the knot quandles of Suciu's ribbon $n$-knots, an infinite family of knots with isomorphic knot groups. We prove that their knot quandles are mutually non-isomorphic.…

Geometric Topology · Mathematics 2025-08-22 Jumpei Yasuda

A. Casson defined an intersection number invariant which can be roughly thought of as the number of conjugacy classes of irreducible representations of $\pi_1(Y)$ into $SU(2)$ counted with signs, where $Y$ is an oriented integral homology…

q-alg · Mathematics 2008-02-03 Weiping Li

In this paper we construct an infinite family of knots with vanishing Upsilon invariant $\Upsilon$, although their secondary Upsilon invariants $\Upsilon^2$ show that they are linearly independent in the smooth knot concordance group. We…

Geometric Topology · Mathematics 2021-08-25 Xiaoyu Xu

We introduce a multivariable Casson-Lin type invariant for links in $S^3$. This invariant is defined as a signed count of irreducible $\operatorname{SU}(2)$ representations of the link group with fixed meridional traces. For 2-component…

Geometric Topology · Mathematics 2019-09-23 Léo Bénard , Anthony Conway

We employ the sl(2) foam cohomology to define a cohomology theory for oriented framed tangles whose components are labelled by irreducible representations of U_q(sl(2)). We show that the corresponding colored invariants of tangles can be…

Geometric Topology · Mathematics 2015-04-01 Carmen Caprau

R. Kashaev and N. Reshetikhin introduced the notion of holonomy braiding extending V. Turaev's homotopy braiding to describe the behavior of cyclic representations of the unrestricted quantum group $U_qsl_2$ at root of unity. In this paper,…

Geometric Topology · Mathematics 2018-06-08 Christian Blanchet , Nathan Geer , Bertrand Patureau-Mirand , Nicolai Reshetikhin

We define a set of "second-order" L^(2)-signature invariants for any algebraically slice knot. These obstruct a knot's being a slice knot and generalize Casson-Gordon invariants, which we consider to be "first-order signatures". As one…

Geometric Topology · Mathematics 2010-04-06 Tim Cochran , Shelly Harvey , Constance Leidy

There is an infinitely generated free subgroup of the smooth knot concordance group with the property that no nontrivial element in this subgroup can be represented by an alternating knot. This subgroup has the further property that every…

Geometric Topology · Mathematics 2017-07-21 Stefan Friedl , Charles Livingston , Raphael Zentner

We call a knot in the 3-sphere $SU(2)$-simple if all representations of the fundamental group of its complement which map a meridian to a trace-free element in $SU(2)$ are binary dihedral. This is a generalisation of being a 2-bridge knot.…

Geometric Topology · Mathematics 2017-02-15 Raphael Zentner

In this paper, we explore the bounded cohomology of quandles and its applications to knot theory. We establish two key results that provide sufficient conditions for the infinite dimensionality of the second bounded cohomology of quandles.…

Geometric Topology · Mathematics 2025-02-25 Deepanshi Saraf , Mahender Singh

This paper is a survey of several papers in quandle homology theory and cocycle knot invariants that have been published recently. Here we describe cocycle knot invariants that are defined in a state-sum form, quandle homology, and methods…

Geometric Topology · Mathematics 2007-05-23 J. Scott Carter , Masahico Saito

While knotoids on the sphere are well-understood by a variety of invariants, knotoids on the plane have proven more subtle to classify due to their multitude over knotoids on the sphere and a lack of invariants that detect a diagram's…

Geometric Topology · Mathematics 2024-07-11 Mohamed Elhamdadi , Wout Moltmaker , Masahico Saito

For a knot K in S^3 we construct according to Casson--or more precisely taking into account Lin and Heusener's further works--a volume form on the SU(2)-representation space of the group of K. We prove that this volume form is a topological…

Geometric Topology · Mathematics 2009-03-06 Jerome Dubois

We construct a novel invariant of braids and knots, secant-quandle (SQ),with generic secants serving as generators and generic horizontal trisecants serving as relations, i.e., $SQ = \Gamma \left< \mathcal{S}_M\mid…

Geometric Topology · Mathematics 2026-03-27 Yangzhou Liu , Seongjeong Kim , Vassily Olegovich Manturov
‹ Prev 1 2 3 10 Next ›