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A graph property is monotone if it is closed under removal of vertices and edges. In this paper we consider the following edge-deletion problem; given a monotone property P and a graph G, compute the smallest number of edge deletions that…

Combinatorics · Mathematics 2007-07-03 Noga Alon , Asaf Shapira , Benny Sudakov

The local $h^*$-polynomial of a lattice polytope is an important invariant arising in Ehrhart theory. Our focus is on lattice simplices presented in Hermite normal form with a single non-trivial row. We prove that when the off-diagonal…

We study the computational limits of the following general hypothesis testing problem. Let H=H_n be an \emph{arbitrary} undirected graph on n vertices. We study the detection task between a ``null'' Erd\H{o}s-R\'{e}nyi random graph G(n,p)…

Statistics Theory · Mathematics 2024-03-27 Xifan Yu , Ilias Zadik , Peiyuan Zhang

We study a class of polynomials that has all of its roots on the critical line and shares many properties with Ehrhart polynomials. Braun showed that the roots of Ehrhart polynomials are bounded quadratically and Higashitani provided…

Combinatorics · Mathematics 2022-07-19 Max Kölbl

We introduce a new matroid (graph) invariant, the arboricity polynomial. Given a matroid, the arboricity polynomial enumerates the number of covers of the ground set by disjoint independent sets. We establish the polynomiality of the…

Combinatorics · Mathematics 2025-05-09 Felix Breuer , Caroline J Klivans

We study graphs of polynomial growth from the perspective of asymptotic geometry and descriptive set theory. The starting point of our investigation is a theorem of Krauthgamer and Lee who showed that every connected graph of polynomial…

Combinatorics · Mathematics 2025-04-08 Anton Bernshteyn , Jing Yu

We study the problem of enumerating all rooted directed spanning trees (arborescences) of a directed graph (digraph) $G=(V,E)$ of $n$ vertices. An arborescence $A$ consisting of edges $e_1,\ldots,e_{n-1}$ can be represented as a monomial…

Data Structures and Algorithms · Computer Science 2024-08-06 Matúš Mihalák , Przemysław Uznański , Pencho Yordanov

The matching polytope of a graph $G$ is the convex hull of the indicator vectors of the matchings on $G$. We characterize the graphs whose associated matching polytopes are Gorenstein, and then prove that all Gorenstein matching polytopes…

Combinatorics · Mathematics 2024-07-15 Benjamin Eisley , Koji Matsushita , Andrés R. Vindas-Meléndez

In this paper, we present new incremental algorithms for maintaining data structures that represent all connectivity cuts of size one in directed graphs (digraphs), and the strongly connected components that result by the removal of each of…

Data Structures and Algorithms · Computer Science 2018-03-01 Loukas Georgiadis , Giuseppe F. Italiano , Nikos Parotsidis

We use the method of steepest descents to study the root distribution of the Ehrhart polynomial of the $d$-dimensional cross-polytope, namely $\mathcal{L}_{d}$, as $d\rightarrow \infty$. We prove that the distribution function of the roots,…

Combinatorics · Mathematics 2010-12-13 Miguel Rodriguez

In this work, we relate girth and path-degeneracy in classes with sub-exponential expansion, with explicit bounds for classes with polynomial expansion and proper minor-closed classes that are tight up to a constant factor (and tight up to…

Combinatorics · Mathematics 2025-03-25 Y. Lin , P. Ossona de Mendez

Many hard algorithmic problems dealing with graphs, circuits, formulas and constraints admit polynomial-time upper bounds if the underlying graph has small treewidth. The same problems often encourage reducing the maximal degree of vertices…

Discrete Mathematics · Computer Science 2011-11-04 Igor Markov , Yaoyun Shi

For a graph invariant $\pi$, the Contraction($\pi$) problem consists in, given a graph $G$ and two positive integers $k,d$, deciding whether one can contract at most $k$ edges of $G$ to obtain a graph in which $\pi$ has dropped by at least…

Data Structures and Algorithms · Computer Science 2021-03-23 Paloma T. Lima , Vinicius F. dos Santos , Ignasi Sau , Uéverton S. Souza

We generalize two main theorems of matching polynomials of undirected simple graphs, namely, real-rootedness and the Heilmann-Lieb root bound. Viewing the matching polynomial of a graph $G$ as the independence polynomial of the line graph…

Combinatorics · Mathematics 2019-02-20 Jonathan Leake , Nick Ryder

Every generic linear functional $f$ on a convex polytope $P$ induces an orientation on the graph of $P$. From the resulting directed graph one can define a notion of $f$-arborescence and $f$-monotone path on $P$, as well as a natural graph…

Combinatorics · Mathematics 2021-04-26 Christos Athanasiadis , Jesús De Loera , Zhenyang Zhang

Roots of graph polynomials such as the characteristic polynomial, the chromatic polynomial, the matching polynomial, and many others are widely studied. In this paper we examine to what extent the location of these roots reflects the graph…

Combinatorics · Mathematics 2013-10-08 Johann A. Makowsky , Elena V. Ravve , Nicolas K. Blanchard

In this paper, we compare the $\mathrm{v}$-numbers and the degree of the $h$-polynomials associated with edge ideals of connected graphs. We prove that the $\mathrm{v}$-number can be arbitrarily larger or smaller than the degree of the…

Commutative Algebra · Mathematics 2025-07-21 Kamalesh Saha , Adam Van Tuyl

In this paper, we focus on the study of immanantal polynomials for linear combination matrices composed of the degree matrix and adjacency matrix of a graph. First, applying the concept of vertex orientation for general graphs, we provide a…

Combinatorics · Mathematics 2026-04-07 Xiangshuai Dong , Tingzeng Wu

Symmetric edge polytopes of graphs are important object in Ehrhart theory,and have an application to Kuramoto models. In the present paper, we study the upper and lower bounds for the number of facets of symmetric edge polytopes of…

Combinatorics · Mathematics 2025-05-01 Aki Mori , Kenta Mori , Hidefumi Ohsugi

We study graph parameters whose associated edge-connection matrices have exponentially bounded rank growth. Our main result is an explicit construction of a large class of graph parameters with this property that we call mixed partition…

Combinatorics · Mathematics 2020-06-16 Guus Regts , Bart Sevenster