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Related papers: On Character varieties of two-bridge knot groups

200 papers

We show that the $(4,5)$- and $(5,6)$-torus knots admit ghost characters. Consequently, these knots provide counterexamples to Ng's conjecture, which proposes an isomorphism between the complexification of degree $0$ abelian knot contact…

Geometric Topology · Mathematics 2026-02-20 Fumikazu Nagasato , Shinnosuke Suzuki

We investigate the existence of some affine structure on SL 2 (C)-character varieties on the four-punctured sphere through web and symplectic geometry. This work provides a new proof of non integrability (i.e. irreducibility) of…

Algebraic Geometry · Mathematics 2025-07-11 Adjaratou Arame Diaw , Karamoko Diarra , Frank Loray , Tangue Ndawa Bertuel

We consider vector fields on knot/link complements in $S^3$ which are transverse to the fibres of a fibration of the complement over a circle. We prove that a large class of fibred knots/links, including all non-torus fibred 2-bridge knots,…

Geometric Topology · Mathematics 2007-05-23 R. Ghrist , E. Kin

We determine the PSL_2(C) and SL_2(C) character varieties of the once-punctured torus bundles with tunnel number one, i.e. the once-punctured torus bundles that arise from filling one boundary component of the Whitehead link exterior. In…

Geometric Topology · Mathematics 2012-11-20 Kenneth L. Baker , Kathleen L. Petersen

We study the twisted Alexander polynomial $\Delta_{K,\rho}$ of a knot $K$ associated to a non-abelian representation $\rho$ of the knot group into $SL_2(\BC)$. It is known for every knot $K$ that if $K$ is fibered, then for every…

Geometric Topology · Mathematics 2013-09-05 Anh T. Tran

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

For every genus $g\geq 2$, we construct an infinite family of strongly quasipositive fibred knots having the same Seifert form as the torus knot $T(2,2g+1)$. In particular, their signatures and four-genera are maximal and their homological…

Geometric Topology · Mathematics 2021-05-27 Filip Misev

In this paper, we study a special family of $(1,1)$ knots called constrained knots, which includes 2-bridge knots in the 3-sphere $S^3$ and simple knots in lens spaces. Constrained knots are parameterized by five integers and characterized…

Geometric Topology · Mathematics 2023-06-14 Fan Ye

We study the structure underlying Ng's conjecture, which relates the degree $0$ abelian knot contact homology of a knot $K$ to the coordinate ring of the $SL_2(\mathbf{C})$-character variety $X(\Sigma_2 K)$ of the $2$-fold branched cover of…

Geometric Topology · Mathematics 2026-02-20 Fumikazu Nagasato

We study the relationship between Ng's abelian cord ring and SL(2,C) characters of the two-fold branched cover $\Sigma(K)$. Augmentations, and their corresponding rank, play a central role in the relationship. Our study also leads to a…

Geometric Topology · Mathematics 2015-09-17 Christopher R. Cornwell

In this paper we consider some families of links, including (-2,2m+1,2n)-pretzel links and twisted Whitehead links. We calculate the character varieties of these families, and determine the number of irreducible components of these…

Geometric Topology · Mathematics 2014-03-27 Anh T. Tran

We give a description of several representation varieties of the fundamental group of the complement of the figure eight knot in PGL(3,C) or SL(3,C). We moreover obtain an explicit parametrization of matrices generating the representation…

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

We give explicit equations that describe the character variety of the figure eight knot for the groups SL(3,C), GL(3,C) and PGL(3,C). This has five components of dimension 2, one consisting of totally reducible representations, another one…

Geometric Topology · Mathematics 2015-05-19 Michael Heusener , Vicente Munoz , Joan Porti

Let $K,K'$ be two-bridge knots of genus $n,k$ respectively. We show the necessary and sufficient condition of $n$ in terms of $k$ that there exists an epimorphism from the knot group of $K$ onto that of $K'$.

Geometric Topology · Mathematics 2017-07-13 Masaaki Suzuki , Anh T. Tran

We classify genus-two L-space knots in the Poincar\'e homology sphere. This leads to the second knot Floer homology detection result for a knot of genus at least two, and the first such result outside of $S^3$. The argument uses the theory…

Geometric Topology · Mathematics 2023-06-02 Braeden Reinoso

We investigate great circle links in the three-sphere, the class of links where each component is a great circle. Using the geometry of their complements, we classify such links up to five components. For any two-bridge knot complement,…

Geometric Topology · Mathematics 2007-05-23 Genevieve Walsh

We study when the Thurston norm is detected by twisted Alexander polynomials associated to representations of the 3-manifold group to SL(2, C). Specifically, we show that the hyperbolic torsion polynomial determines the genus for a large…

Geometric Topology · Mathematics 2015-03-06 Ian Agol , Nathan M. Dunfield

In this paper we apply the twisted Alexander polynomial to study the fibering and genus detecting problems for oriented links. In particular we generalize a conjecture of Dunfield, Friedl and Jackson on the torsion polynomial of hyperbolic…

Geometric Topology · Mathematics 2016-10-24 Takayuki Morifuji , Anh T. Tran

In this paper, we consider generalizations of the Alexander polynomial and signature of 2-bridge knots by considering the Gordon-Litherland bilinear forms associated to essential state surfaces of the 2-bridge knots. We show that the…

Geometric Topology · Mathematics 2017-10-30 Cynthia L. Curtis , Vincent Longo