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Related papers: Tutte Short Exact Sequences of Graphs

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This paper deals with the location of the complex zeros of the Tutte polynomial for a class of self-dual graphs. For this class of graphs, as the form of the eigenvalues is known, the regions of the complex plane can be focused on the sets…

Combinatorics · Mathematics 2009-05-19 Jean-Michel Billiot , Franck Corset , Eric Fontenas

We give a necessary and sufficient graph-theoretic characterization of toric ideals of graphs that are unimodular. As a direct consequence, we provide the structure of unimodular graphs by proving that the incidence matrix of a graph $G$ is…

Commutative Algebra · Mathematics 2025-10-15 Christos Tatakis

The number of homomorphisms from a finite graph $F$ to the complete graph $K_n$ is the evaluation of the chromatic polynomial of $F$ at $n$. Suitably scaled, this is the Tutte polynomial evaluation $T(F;1-n,0)$ and an invariant of the cycle…

Combinatorics · Mathematics 2016-02-25 Andrew Goodall , Guus Regts , Lluis Vena

In 1954, Tutte conjectured that every bridgeless graph has a nowhere-zero 5-flow. Let $\omega$ be the minimum number of odd cycles in a 2-factor of a bridgeless cubic graph. Tutte's conjecture is equivalent to its restriction to cubic…

Combinatorics · Mathematics 2012-09-21 Eckhard Steffen

We prove that every postsingularly finite entire map $g$ can be approximated by a sequence of postcritically finite complex polynomials $(g_n)$ such that their postsingular dynamics $g|P_g$ and $g_n|P_{g_n}$ are conjugate for every $n \in…

Dynamical Systems · Mathematics 2024-01-17 Malavika Mukundan , Nikolai Prochorov , Bernhard Reinke

Motivated by circle graphs, and the enumeration of Euler circuits, we define a one-variable ``interlace polynomial'' for any graph. The polynomial satisfies a beautiful and unexpected reduction relation, quite different from the cut and…

Combinatorics · Mathematics 2007-05-23 Richard Arratia , Bela Bollobas , Gregory B. Sorkin

We classify modules and rings with some specific properties of their intersection graphs. In particular, we describe rings with infinite intersection graphs containing maximal left ideals of finite degree. This answers a question raised in…

Rings and Algebras · Mathematics 2017-07-26 Jerzy Matczuk , Marta Nowakowska , Edmund R. Puczyłowski

We prove some variants of the exponential formula and apply them to the multivariate Tutte polynomials (also known as Potts-model partition functions) of graphs. We also prove some further identities for the multivariate Tutte polynomial,…

Combinatorics · Mathematics 2009-11-16 Alexander D. Scott , Alan D. Sokal

The tensor product $(G_1,G_2)$ of a graph $G_1$ and a pointed graph $G_2$ (containing one distinguished edge) is obtained by identifying each edge of $G_1$ with the distinguished edge of a separate copy of $G_2$, and then removing the…

Combinatorics · Mathematics 2014-06-10 Yuanan Diao , Gábor Hetyei

We introduce and study the notion of the $G$-Tutte polynomial for a list $\mathcal{A}$ of elements in a finitely generated abelian group $\Gamma$ and an abelian group $G$, which is defined by counting the number of homomorphisms from…

Combinatorics · Mathematics 2021-09-03 Ye Liu , Tan Nhat Tran , Masahiko Yoshinaga

For G an almost-connected Lie group, we study G-equivariant index theory for proper co-compact actions with various applications, including obstructions to and existence of G-invariant Riemannian metrics of positive scalar curvature. We…

K-Theory and Homology · Mathematics 2020-02-06 Hao Guo , Varghese Mathai , Hang Wang

Tutte's spring embedding theorem states that, for a three-connected planar graph, if the outer face of the graph is fixed as the complement of some convex region in the plane, and all other vertices are placed at the mass center of their…

Combinatorics · Mathematics 2020-07-10 John C. Urschel , Ludmil T. Zikatanov

The classical Tutte polynomial is a two-variate polynomial $T_G(x,y)$ associated to graphs or more generally, matroids. In this paper, we introduce a polynomial $\widetilde{T}_H(x,y)$ associated to a bipartite graph $H$ that we call the…

Combinatorics · Mathematics 2024-05-08 Csongor Beke , Gergely Kál Csáji , Péter Csikvári , Sára Pituk

Let $G=(V,E)$ be a finite, simple graph. We consider for each oriented graph $G_{\cal O}$ associated to an orientation ${\cal O}$ of the edges of $G$, the toric ideal $P_{G_{\cal O}}$. In this paper we study those graphs with the property…

Commutative Algebra · Mathematics 2013-01-01 I. Gitler , E. Reyes , J. A. Vega

Our purpose is to study the family of simple undirected graphs whose toric ideal is a complete intersection from both an algorithmic and a combinatorial point of view. We obtain a polynomial time algorithm that, given a graph $G$, checks…

Commutative Algebra · Mathematics 2015-07-14 Isabel Bermejo , Ignacio García-Marco , Enrique Reyes

The block-cut tree decomposes a connected graph along its cutvertices, displaying its 2-connected components. The Tutte-decomposition extends this idea to 2-separators in 2-connected graphs, yielding a canonical tree-decomposition that…

Data Structures and Algorithms · Computer Science 2025-08-11 Romain Bourneuf , Tim Planken

Considering the worst-case scenario, junction tree algorithm remains the most general solution for exact MAP inference with polynomial run-time guarantees. Unfortunately, its main tractability assumption requires the treewidth of a…

Discrete Mathematics · Computer Science 2022-02-10 Alexander Bauer , Shinichi Nakajima

The two operations, deletion and contraction of an edge, on multigraphs directly lead to the Tutte polynomial which satisfies a universal problem. As observed by Brylawski in terms of order relations, these operations may be interpreted as…

Discrete Mathematics · Computer Science 2013-03-08 Laurent Poinsot

We introduce two graph polynomials and discuss their properties. One is a polynomial of two variables whose investigation is motivated by the performance analysis of the Bethe approximation of the Ising partition function. The other is a…

Combinatorics · Mathematics 2010-06-07 Yusuke Watanabe , Kenji Fukumizu

In this paper, new graphs $G_\tau=\left(V,E\right)$ are constructed from the discrete topological space $(X,\tau)\ $ . Several properties of this type of graphs are given such that: the clique number equals the number of elements in X also…

Combinatorics · Mathematics 2022-11-15 Ahmed A. Omran , Veena Mathad , Ammar Alsinai , Mohammed A. Abdlhusein