English
Related papers

Related papers: A symmetric function approach to log-concavity of …

200 papers

We prove that the generating function for the symmetric chromatic polynomial of all connected graphs satisfies (after appropriate scaling change of variables) the Kadomtsev--Petviashvili integrable hierarchy of mathematical physics.…

Combinatorics · Mathematics 2018-05-16 Sergei Chmutov , Maxim Kazarian , Sergey Lando

A polynomial is said to be unimodal if its coefficients are non-decreasing and then non-increasing. The domination polynomial of a graph $G$ is the generating function of the number of dominating sets of each cardinality in $G$. In…

Combinatorics · Mathematics 2024-11-05 Iain Beaton , Sam Schoonhoven

Stanley introduced the concept of chromatic symmetric functions of graphs which extends and refines the notion of chromatic polynomials of graphs, and asked whether trees are determined up to isomorphism by their chromatic symmetric…

Combinatorics · Mathematics 2024-02-21 Yuzhenni Wang , Xingxing Yu , Xiao-Dong Zhang

Given two graphs $G$ and $H$, assume that $\mathscr{C}=\{C_1,C_2,\ldots, C_q\}$ is a clique cover of $G$ and $U$ is a subset of $V(H)$. We introduce a new graph operation called the clique cover product, denoted by $G^{\mathscr{C}}\star…

Combinatorics · Mathematics 2013-10-01 Bao-Xuan Zhu

The chromatic polynomial is a well studied object in graph theory. There are many results and conjectures about the log-concavity of the chromatic polynomial and other polynomials related to it. The location of the roots of these…

Combinatorics · Mathematics 2011-05-05 Sukhada Fadnavis

We identify a structural pattern in the construction of known infinite families of trees whose independence polynomials are not log-concave. Using this pattern and properties of polynomial ring ideals, we derive linear recurrences for these…

Combinatorics · Mathematics 2026-03-17 César Bautista-Ramos , Carlos Guillén-Galván , Paulino Gómez-Salgado

In [1] Peters and Regts confirmed a conjecture by Sokal by showing that for every $\Delta \in \mathbb{Z}_{\geq 3}$ there exists a complex neighborhood of the interval $\left[0, \frac{\left(\Delta - 1\right)^{\Delta -…

Combinatorics · Mathematics 2019-03-14 Pjotr Buys

Given $n \geq 1$, we study the existence of a tree on $n$ vertices whose independence polynomial is symmetric and unimodal as well as the existence of a symmetric and unimodal independence polynomial of degree $n$ of a tree.

Combinatorics · Mathematics 2026-04-22 Takayuki Hibi , Selvi Kara , Dalena Vien

In 1936, Margarete C. Wolf showed that the ring of symmetric free polynomials in two or more variables is isomorphic to the ring of free polynomials in infinitely many variables. We show that Wolf's theorem is a special case of a general…

Functional Analysis · Mathematics 2014-09-09 David Cushing , J. E. Pascoe , Ryan Tully-Doyle

Motivated by the necessities of the invariant theory of binary forms J. J. Sylvester constructed in 1878 for each graph with possible multiple edges but without loops its symmetrized graph monomial which is a polynomial in the vertex labels…

Algebraic Geometry · Mathematics 2015-12-14 Per Alexandersson , Boris Shapiro

Stanley introduced the chromatic symmetric function of a simple graph, which is a generalization of a chromatic polynomial. This is expressed in terms of the integer points of the complements of the corresponding graphic arrangement.…

Combinatorics · Mathematics 2021-03-05 Masamichi Kuroda , Shuhei Tsujie

In this article we consider certain well-known polynomials associated with graphs including the independence polynomial and the chromatic polynomial. These polynomials count certain objects in graphs: independent sets in the case of the…

Data Structures and Algorithms · Computer Science 2022-12-19 Viresh Patel , Guus Regts

The independence polynomial of a graph is the generating polynomial for the number of independent sets of each size, and its roots are called {\em independence roots}. We investigate the stability of such polynomials, that is, conditions…

Combinatorics · Mathematics 2018-02-08 Jason Brown , Ben Cameron

The chromatic polynomial is characterized as the unique polynomial invariant of graphs, compatible with two interacting bialgebras structures: the first coproduct is given by partitions of vertices into two parts, the second one by a…

Rings and Algebras · Mathematics 2021-05-05 Loïc Foissy

The independence polynomial $I(G,x)$ of a finite graph $G$ is the generating function for the sequence of the number of independent sets of each cardinality. We investigate whether, given a fixed number of vertices and edges, there exists…

Combinatorics · Mathematics 2017-10-11 J. I. Brown , D. Cox

The main result of this paper is the introduction of marked graphs and the marked graph polynomials ($M$-polynomial) associated with them. These polynomials can be defined via a deletion-contraction operation. These polynomials are a…

Combinatorics · Mathematics 2022-02-25 José Aliste-Prieto , Anna de Mier , Rosa Orellana , José Zamora

We define the acyclic orientation polynomial of a graph to be the generating function for the sinks of its acyclic orientations. Stanley proved that the number of acyclic orientations is equal to the chromatic polynomial evaluated at $-1$…

Combinatorics · Mathematics 2020-08-25 Byung-Hak Hwang , Woo-Seok Jung , Kang-Ju Lee , Jaeseong Oh , Sang-Hoon Yu

In this paper, we propose an algebraic approach to determine whether two non-isomorphic caterpillar trees can have the same symmetric function generalization of the chromatic polynomial. On the set of all composition on integers, we…

Combinatorics · Mathematics 2012-08-09 José Aliste-Prieto , José Zamora

This paper investigates the independence polynomials arising from iterated strong products of cycle graphs, examining their algebraic symmetries and combinatorial structures. Leveraging modular arithmetic and Galois theory, we establish…

Combinatorics · Mathematics 2026-01-13 Todd Hildebrant

A graph is well-covered if all its maximal independent sets are of the same cardinality (Plummer, 1970). If G is a well-covered graph, has at least two vertices, and G-v is well-covered for every vertex v, then G is a 1-well-covered graph…

Combinatorics · Mathematics 2016-12-13 Vadim E. Levit , Eugen Mandrescu