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Related papers: A Dirac-type Characterization of k-chordal Graphs

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A bipartite graph is chordal bipartite if every cycle of length at least six has a chord in it. M$\ddot{\rm u}$ller \cite {muller1996Hamiltonian} has shown that the Hamiltonian cycle problem is NP-complete on chordal bipartite graphs by…

Discrete Mathematics · Computer Science 2021-07-13 S. Aadhavan , R. Mahendra Kumar , P. Renjith , N. Sadagopan

In this paper, we characterize the degree sequences excluding the degree sequence of a square in terms of forcibly chordal graphs, and we prove several related results.

Combinatorics · Mathematics 2011-10-20 Christian Joseph Altomare

It is known that if G is a connected simple graph, then G^3 is Hamiltonian (in fact, Hamilton-connected). A simple graph is k-ordered Hamiltonian if for any sequence v_1, v_2, ..., v_k of k vertices there is a Hamiltonian cycle containing…

Combinatorics · Mathematics 2007-05-23 Denis Chebikin

Many NP-Hard problems on general graphs, such as maximum independence set, maximal cliques and graph coloring can be solved efficiently on chordal graphs. In this paper, we explore the problem of non-separating st-paths defined on edges:…

Data Structures and Algorithms · Computer Science 2021-02-10 Xiao Mao

This paper is the first from serial papers that provide constructive characterizations for classes of bidirected graphs known as radials and semiradials. In this paper, we provide constructive characterizations for five principle classes of…

Combinatorics · Mathematics 2020-01-03 Nanao Kita

The generalized $k$-connectivity $\kappa_k(G)$ of a graph $G$ was introduced by Chartrand et al. in 1984, which is a nice generalization of the classical connectivity. Recently, as a natural counterpart, Li et al. proposed the concept of…

Combinatorics · Mathematics 2013-04-24 Lily Chen , Xueliang Li , Mengmeng Liu , Yaping Mao

We examine $t$-colourings of oriented graphs in which, for a fixed integer $k \geq 1$, vertices joined by a directed path of length at most $k$ must be assigned different colours. A homomorphism model that extends the ideas of Sherk for the…

Discrete Mathematics · Computer Science 2023-06-22 Christopher Duffy , Gary MacGillivray , Éric Sopena

For a digraph $D$ of order $n$ and an integer $1 \leq k \leq n-1$, the $k$-token digraph of $D$ is the graph whose vertices are all $k$-subsets of vertices of $D$ and, given two such $k$-subsets $A$ and $B$, $(A,B)$ is an arc in the…

Graph classification aims to categorise graphs based on their structure and node attributes. In this work, we propose to tackle this task using tools from graph signal processing by deriving spectral features, which we then use to design…

Machine Learning · Computer Science 2023-06-07 Felix L. Opolka , Yin-Cong Zhi , Pietro Liò , Xiaowen Dong

A graph is said to be globally rigid if almost all embeddings of the graph's vertices in the Euclidean plane will define a system of edge-length equations with a unique (up to isometry) solution. In 2007, Jackson, Servatius and Servatius…

Combinatorics · Mathematics 2024-01-29 Sean Dewar

Highly-regular graphs can be regarded as a combinatorial generalization of distance-regular graphs. From this standpoint, we study combinatorial aspects of highly-regular graphs. As a result, we give the following three main results in this…

Combinatorics · Mathematics 2017-10-06 Taichi Kousaka

We develop a necessary and sufficient causal identification criterion for maximally oriented partially directed acyclic graphs (MPDAGs). MPDAGs as a class of graphs include directed acyclic graphs (DAGs), completed partially directed…

Statistics Theory · Mathematics 2025-07-23 Emilija Perković

We study the problem of finding a Hamiltonian cycle under the promise that the input graph has a minimum degree of at least $n/2$, where $n$ denotes the number of vertices in the graph. The classical theorem of Dirac states that such graphs…

Distributed, Parallel, and Cluster Computing · Computer Science 2023-07-24 Noy Biton , Reut Levi , Moti Medina

Given any digraph $D$ on $n$ vertices, let $\mathcal{P}(D)$ be the family of all directed paths in $D$, and let $H$ be a digraph with the arc set $A(H)=\{a_1, \ldots, a_k\}$. The digraph $D$ is called arbitrary Hamiltonian $H$-linked if for…

Combinatorics · Mathematics 2025-03-27 Yangyang Cheng , Zhilan Wang , Jin Yan

A sequence $D=(d_1,d_2,\ldots,d_n)$ of non-negative integers is called a graphic sequence if there is a simple graph with vertices $v_1,v_2,\ldots,v_n$ such that the degree of $v_i$ is $d_i$ for $1\leq i\leq n$. Given a graph theoretical…

Combinatorics · Mathematics 2025-04-23 Peiyi Duan , Yingzhi Tian

Introduced the quantitative measure of the structural complexity of the graph (complex network, etc.) based on a procedure similar to the renormalization process, considering the difference between actual and averaged graph structures on…

Physics and Society · Physics 2024-06-05 A. A. Snarskii

The human brain cortical layer has a convoluted morphology that is unique to each individual. Characterization of the cortical morphology is necessary in longitudinal studies of structural brain change, as well as in discriminating…

Neurons and Cognition · Quantitative Biology 2019-02-21 Sevil Maghsadhagh , Anders Eklund , Hamid Behjat

A bipartite graph is chordal bipartite if every cycle of length at least 6 has a chord in it. In this paper, we investigate the structure of $P_5$-free chordal bipartite graphs and show that these graphs have a Nested Neighborhood Ordering,…

Discrete Mathematics · Computer Science 2017-12-27 S Aadhavan , P Renjith , N Sadagopan

Graphs are commonly used to represent and visualize causal relations. For a small number of variables, this approach provides a succinct and clear view of the scenario at hand. As the number of variables under study increases, the graphical…

Machine Learning · Statistics 2023-08-16 Santtu Tikka , Jouni Helske , Juha Karvanen

It is known (Bollob\'{a}s (1978); Kostochka and Mazurova (1977)) that there exist graphs of maximum degree $\Delta$ and of arbitrarily large girth whose chromatic number is at least $c \Delta / \log \Delta$. We show an analogous result for…

Combinatorics · Mathematics 2011-10-25 Ararat Harutyunyan , Bojan Mohar