English
Related papers

Related papers: On the treewidth of generalized Kneser graphs

200 papers

The matching number of a $k$-graph is the maximum number of pairwise disjoint edges in it. The $k$-graph is called $t$-resilient if omitting $t$ vertices never decreases its matching number. The complete $k$-graph on $sk+k-1$ vertices has…

Combinatorics · Mathematics 2025-03-12 Peter Frankl , Jian Wang

We describe a polynomial-time algorithm which, given a graph $G$ with treewidth $t$, approximates the pathwidth of $G$ to within a ratio of $O(t\sqrt{\log t})$. This is the first algorithm to achieve an $f(t)$-approximation for some…

Data Structures and Algorithms · Computer Science 2023-03-13 Carla Groenland , Gwenaël Joret , Wojciech Nadara , Bartosz Walczak

In this paper, all graphs whose adjacency matrix has at most two eigenvalues (multiplicities included) different from $2$ and $-1$ are determined. These graphs conclude a class of generalized friendship graphs $F_{t,r,k}, $ which is the…

Combinatorics · Mathematics 2018-06-20 Jing Li , Deqiong Li , Yaoping Hou

We study the existence of polynomial kernels, for parameterized problems without a polynomial kernel on general graphs, when restricted to graphs of bounded twin-width. Our main result is that a polynomial kernel for $k$-Dominating Set on…

Data Structures and Algorithms · Computer Science 2021-09-15 Édouard Bonnet , Eun Jung Kim , Amadeus Reinald , Stéphan Thomassé , Rémi Watrigant

Let $S$ be a nonempty set of vertices of a connected graph $G$. A collection $T_1,..., T_\ell$ of trees in $G$ is said to be internally disjoint trees connecting $S$ if $E(T_i)\cap E(T_j)= \emptyset$ and $V(T_i)\cap V(T_j)=S$ for any pair…

Combinatorics · Mathematics 2012-01-17 Hengzhe Li , Xueliang Li , Yaping Mao , Yuefang Sun

A set of vertices $S$ is a \emph{determining set} of a graph $G$ if every automorphism of $G$ is uniquely determined by its action on $S$. The \emph{determining number} of $G$ is the minimum cardinality of a determining set of $G$. This…

Combinatorics · Mathematics 2011-11-15 J. Cáceres , D. Garijo , A. González , A. Márquez , M. L. Puertas

The Linear Arboricity Conjecture asserts that the linear arboricity of a graph with maximum degree $\Delta$ is $\lceil (\Delta+1)/2 \rceil$. For a $2k$-regular graph $G$, this implies $la(G) = k+1$. In this note, we utilize a network flow…

Combinatorics · Mathematics 2025-12-15 Tapas Kumar Mishra

Let $T$ be a distinguished subset of vertices in a graph $G$. A $T$-\emph{Steiner tree} is a subgraph of $G$ that is a tree and that spans $T$. Kriesell conjectured that $G$ contains $k$ pairwise edge-disjoint $T$-Steiner trees provided…

Combinatorics · Mathematics 2015-08-11 Matt DeVos , Jessica McDonald , Irene Pivotto

In this paper, we study some spanning trees with bounded degree and leaf degree from eigenvalues. For any integer $k\geq2$, a $k$-tree is a spanning tree in which every vertex has degree no more than $k$. Let $T$ be a spanning tree of a…

Combinatorics · Mathematics 2024-07-29 Chang Liu , Jianping Li

A graph that contains a spanning tree of diameter at most $t$ clearly admits a tree $t$-spanner, since a tree $t$-spanner of a graph $G$ is a sub tree of $G$ such that the distance between pairs of vertices in the tree is at most $t$ times…

Discrete Mathematics · Computer Science 2015-03-23 Ioannis Papoutsakis

For a positive integer $k$, a graph is $k$-knitted if for each $k$-subset $S$ of vertices, and every partition of $S$ into disjoint parts $S_1, \ldots, S_t$ for some $t\ge 1$, one can find disjoint connected subgraphs $C_1, \ldots, C_t$…

Combinatorics · Mathematics 2019-06-11 Runrun Liu , Martin Rolek , Gexin Yu

A tree is called k-ended tree if it has at most k leaves, where a leaf is a vertex of degree one. In this paper we prove that every 3-regular connected graph with n vertices such that n is greater than 8 has spanning sub tree with at most…

Combinatorics · Mathematics 2016-06-22 Hamed Ghasemian Zoeram , Daniel Yaqubi

We investigate a generalization of the bondage number of a graph called the \textit{$k\,$-synchronous bondage number}. The $k\,$-synchronous bondage number of a graph is the smallest number of edges that, when removed, increases the…

Combinatorics · Mathematics 2022-08-17 Rey Anaya , Alvaro Belmonte , Nathan Shank , Elise Sinani , Bryan Walker

A graph is $k$-clique-extendible if there is an ordering of the vertices such that whenever two $k$-sized overlapping cliques $A$ and $B$ have $k-1$ common vertices, and these common vertices appear between the two vertices $a,b\in…

Data Structures and Algorithms · Computer Science 2020-07-14 Mathew Francis , Rian Neogi , Venkatesh Raman

We show that for any nontrivial knot $K$ and any natural number $n$ there is a diagram $D$ of $K$ such that the unknotting number of $D$ is greater than or equal to $n$. It is well known that twice the unknotting number of $K$ is less than…

Geometric Topology · Mathematics 2008-06-22 Kouki Taniyama

The edge metric dimension problem was recently introduced, which initiated the study of its mathematical properties. The theoretical properties of the edge metric representations and the edge metric dimension of generalized Petersen graphs…

Combinatorics · Mathematics 2019-10-15 Vladimir Filipovic. Aleksandar Kartelj , Jozef Kratica

The k-Tree algorithm [Wagner 02] is a non-trivial algorithm for the average-case k-SUM problem that has found widespread use in cryptanalysis. Its input consists of k lists, each containing n integers from a range of size m. Wagner's…

Cryptography and Security · Computer Science 2024-10-14 Haoxing Lin , Prashant Nalini Vasudevan

We prove that there is $c>0$ such that for all sufficiently large $n$, if $T_1,\dots,T_n$ are any trees such that $T_i$ has $i$ vertices and maximum degree at most $cn/\log n$, then $\{T_1,\dots,T_n\}$ packs into $K_n$. Our main result…

Combinatorics · Mathematics 2022-06-22 Peter Allen , Julia Böttcher , Dennis Clemens , Jan Hladký , Diana Piguet , Anusch Taraz

Let $G=(V,E)$ be a simple, unweighted, connected graph. Let $d(u,v)$ denote the distance between vertices $u,v$. A resolving set of $G$ is a subset $S$ of $V$ such that knowing the distance from a vertex $v$ to every vertex in $S$ uniquely…

Data Structures and Algorithms · Computer Science 2023-02-14 Paul Gutkovich , Zi Song Yeoh

The famous Erd\H{o}s-S\'os conjecture states that every graph of average degree more than $t-1$ must contain every tree on $t+1$ vertices. In this paper, we study a spectral version of this conjecture. For $n>k$, let $S_{n,k}$ be the join…

Combinatorics · Mathematics 2022-06-08 Sebastian Cioabă , Dheer Noal Desai , Michael Tait