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Related papers: Burau maps and twisted Alexander polynomials

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We observe that Clay-Rolfsen's obstruction of bi-orderability, which uses the classical Alexander polynomial, is not strengthened by using the twisted Alexander polynomials for finite representations unlike many known applications of the…

Geometric Topology · Mathematics 2015-01-30 Tetsuya Ito

We compute the Brauer group of some of the known Enriques manifolds. We then build special Brauer-Severi varieties on these manifolds and study the pull-back map from the Brauer group of an Enriques manifold to that of its hyper-K\"ahler…

Algebraic Geometry · Mathematics 2026-05-08 Alessandro Frassineti , Francesca Rizzo , Federico Tufo , Matteo Verni

Graph polynomials encode fundamental combinatorial invariants of graphs. Their computation is investigated using tree and path decomposition frameworks, with formal definitions of treewidth, k-trees, and pathwidth establishing the…

Discrete Mathematics · Computer Science 2025-09-29 Mehul Bafna , Shaghik Amirian

We study a wide range of homologically-defined representations of surface braid groups and of mapping class groups of surfaces, including the Lawrence-Bigelow representations of the classical braid groups. These representations naturally…

Geometric Topology · Mathematics 2025-09-16 Martin Palmer , Arthur Soulié

X.S. Lin's original definition of twisted Alexander knot polynomial is generalized for arbitrary finitely presented groups. J. Cha's fibering obstruction theorem is generalized. The group of a nontrivial virtual knot shown by L. Kauffman to…

Geometric Topology · Mathematics 2009-08-14 Daniel S. Silver , Susan G. Williams

We construct a braided structure on the algebra of K\"ahler differential forms of a commutative algebra twisted by an endomorphism. This generalises the construction done in M. Karoubi, Quantum Methods in Algebraic Topology, see…

Algebraic Topology · Mathematics 2007-05-23 Max Karoubi , Mariano Suarez-Alvarez

We develop some general tools for computing the Brauer group of a tame algebraic stack $\mathscr X$ by studying the difference between it and the Brauer group of the coarse space $X$ of $\mathscr X$. It is our hope that these tools will be…

Algebraic Geometry · Mathematics 2025-07-22 Niven Achenjang

Given a homomorphism from a knot group to a fixed group, we introduce an element of a $K_1$-group, which is a generalization of (twisted) Alexander polynomials. We compare this $K_1$-class with other Alexander polynomials. In terms of…

Geometric Topology · Mathematics 2020-11-24 Takefumi Nosaka

Using the Fourier expansion of Markov traces for Ariki-Koike algebras over $\mathbb{Q}(q,u_{1},...,u_{e})$, we give a direct definition of the Alexander polynomials for mixed links. We observe that under the corresponding specialization of…

Representation Theory · Mathematics 2011-12-13 Hitoshi Yamanaka

We consider birack and switch colorings of braids. We define a switch structure on the set of permutation representations of the braid group and consider when such a representation is a switch automorphism. We define quiver-valued…

Geometric Topology · Mathematics 2024-07-02 Max Chao-Haft , Sam Nelson

Motivated by an observation of Dehornoy, we study the roots of Alexander polynomials of knots and links that are closures of positive 3-strand braids. We give experimental data on random such braids and find that the roots exhibit marked…

Geometric Topology · Mathematics 2025-03-11 Nathan M. Dunfield , Giulio Tiozzo

We consider a braid $\beta$ which acts on a punctured plane. Then we construct a local system on this plane and find a homology cicle $D$ in its symmetric power such that $D\cdot \beta(D)$ coincides with the Alexander polynomial of the…

Algebraic Topology · Mathematics 2015-10-27 Nikita Kalinin

We classify right-veering homeomorphisms of the once-punctured torus using the Burau representation of the 3-strand braid group. We show that reducible and periodic mapping classes in B_3 can be identified as right-veering by consideration…

Geometric Topology · Mathematics 2009-05-30 Emille K. Davie

We study and give examples of braided groupoids, and, a fortiori, non-degenerate solutions of the quiver-theoretical braid equation.

Quantum Algebra · Mathematics 2007-05-23 C. Maldonado , J. M. Mombelli

We prove Alexander- and Markov-type theorems for virtual spatial trivalent graphs and virtual trivalent braids. We provide two versions for the Markov-type theorem: one uses an algebraic approach similar to the case of classical braids and…

Geometric Topology · Mathematics 2019-06-04 Carmen Caprau , Abigayle Dirdak , Rita Post , Erica Sawyer

Twisted knot theory, introduced by M.O. Bourgoin, is a generalization of virtual knot theory. It naturally yields the notion of a twisted braid, which is closely related to the notion of a virtual braid due to Kauffman. In this paper, we…

Geometric Topology · Mathematics 2024-05-28 Shudan Xue , Qingying Deng

We construct an Alexander type invariant for oriented doodles from a deformation of the Tits representation of the twin group and from the Chebyshev polynomials of second kind. Similar to the Alexander polynomial, our invariant vanishes on…

Geometric Topology · Mathematics 2020-09-21 Bruno Cisneros , Marcelo Flores , Jesús Juyumaya , Christopher Roque-Márquez

Hurwitz numbers count covers of curves satisfying fixed ramification data. Via monodromy representation, this counting problem can be transformed to a problem of counting factorizations in the symmetric group. This and other beautiful…

Combinatorics · Mathematics 2023-12-07 Marvin Anas Hahn , Hannah Markwig

We explicitly compute certain Douglas algebras that are invariant under both the Bourgain map and the minimal envelope map. We also compute the Bourgain algebra and the minimal envelope of the maximal subalgebras of a certain singly…

Operator Algebras · Mathematics 2016-09-06 Carroll Guillory

We compute the cohomological Brauer groups of twists of weighted projective spaces and weighted projective stacks.

Algebraic Geometry · Mathematics 2023-07-26 Minseon Shin