English
Related papers

Related papers: Unit Mixed Interval Graphs

200 papers

In this paper, we provide a unified definition of mediated graph, a combinatorial structure with multiple applications in mathematical optimization. We study some geometric and algebraic properties of this family of graphs and analyze…

Optimization and Control · Mathematics 2025-02-06 Víctor Blanco , Miguel Martínez-Antón

Generalizing the notion of split graphs to uniform hypergraphs, we prove that the class of these hypergraphs can be characterized by a finite list of excluded induced subhypergraphs. We show that a characterization by generalized degree…

Combinatorics · Mathematics 2020-05-11 Adam Timar

Multiple interval graphs are a well-known generalization of interval graphs introduced in the 1970s to deal with situations arising naturally in scheduling and allocation. A $d$-interval is the union of $d$ intervals on the real line, and a…

Computational Complexity · Computer Science 2023-09-22 Virginia Ardévol Martínez , Romeo Rizzi , Florian Sikora , Stéphane Vialette

A universal representation theorem is derived that shows any graph is the intersection graph of one chordal graph, a number of co-bipartite graphs, and one unit interval graph. Central to the the result is the notion of the clique cover…

Combinatorics · Mathematics 2015-04-21 Farhad Shahrokhi

The \emph{thinness} of a graph is a width parameter that generalizes some properties of interval graphs, which are exactly the graphs of thinness one. Graphs with thinness at most two include, for example, bipartite convex graphs. Many…

Discrete Mathematics · Computer Science 2023-10-06 Flavia Bonomo-Braberman , Gastón Abel Brito

Inspired by notorious combinatorial optimization problems on graphs, in this paper we consider a series of related problems defined using a metric space and topology determined by a graph. Particularly, we present the Independent Set,…

Combinatorics · Mathematics 2025-07-30 Alexander Grigoriev , Katherine Faulkner

Hypergraphs are structures that can be decomposed or described; in other words they are recursively countable. Here, we get exact and asymptotic enumeration results on hypergraphs by means of exponential generating functions. The number of…

Discrete Mathematics · Computer Science 2008-06-20 Tsiriniaina Andriamampianina

An interval graph is considered improper if and only if it has a representation such that an interval contains another interval. Previously these have been investigated in terms of balance and minimal forbidden interval subgraphs for the…

Combinatorics · Mathematics 2015-05-28 Jeffrey J. Beyerl , Wayne Wallace

Graph-structured data appears frequently in domains including chemistry, natural language semantics, social networks, and knowledge bases. In this work, we study feature learning techniques for graph-structured inputs. Our starting point is…

Machine Learning · Computer Science 2017-09-26 Yujia Li , Daniel Tarlow , Marc Brockschmidt , Richard Zemel

In this paper, we hope to bring closer graph theory and consensus algorithms. Firstly, we give a brief introduction to graph theory by listing a concise definition. Then we analyze and visualize some commonly used graphs. Secondly, we…

Discrete Mathematics · Computer Science 2021-01-27 Shen Zheng

An interval graph is the intersection graph of a finite set of intervals on a line and a circular-arc graph is the intersection graph of a finite set of arcs on a circle. While a forbidden induced subgraph characterization of interval…

Discrete Mathematics · Computer Science 2014-02-12 Luciano N. Grippo , Martín D. Safe

A mixed graph is obtained by orienting some edges of a simple graph. The positive inertia index of a mixed graph is defined as the number of positive eigenvalues of its Hermitian adjacency matrix, including multiplicities. This matrix was…

Combinatorics · Mathematics 2021-02-23 Xiaocong He , Lihua Feng

Strongly chordal graphs are a subclass of chordal graphs. Farber also established a number of different characterisations for this class of graphs. These include an intersection graph characterisation that is analogous to a similar…

Data Structures and Algorithms · Computer Science 2019-09-06 Md. Zamilur Rahman , Asish Mukhopadhyay

We consider drawings of graphs that contain dense subgraphs. We introduce intersection-link representations for such graphs, in which each vertex $u$ is represented by a geometric object $R(u)$ and in which each edge $(u,v)$ is represented…

Data Structures and Algorithms · Computer Science 2015-09-01 Patrizio Angelini , Giordano Da Lozzo , Giuseppe Di Battista , Fabrizio Frati , Maurizio Patrignani , Ignaz Rutter

In this article, we determine the maximum Wiener indices of unicyclic graphs with given number of vertices and matching number. We also characterize the extremal graphs. This solves an open problem of Du and Zhou.

Combinatorics · Mathematics 2018-07-17 Stijn Cambie

In this paper, we introduce a matrix for a mixed graph, called the integrated adjacency matrix. This matrix uniquely determines a mixed graph, as long as the indices of the matrix are specified. Additionally, we associate an (undirected)…

Combinatorics · Mathematics 2025-11-27 G. Kalaivani , R. Rajkumar

In this paper we define critical graphs as minimal graphs that support a given set of rates for the index coding problem, and study them for both the one-shot and asymptotic setups. For the case of equal rates, we find the critical graph…

Information Theory · Computer Science 2014-04-15 Mehrdad Tahmasbi , Amirbehshad Shahrasbi , Amin Gohari

Threshold graphs are recursive deterministic network models that have been proposed for describing certain economic and social interactions. One drawback of this graph family is that it has limited generative attachment rules. To mitigate…

Social and Information Networks · Computer Science 2018-05-24 Vida Ravanmehr , Gregory J. Puleo , Sadegh Bolouki , Olgica Milenkovic

We study the ratio, in a finite graph, of the sizes of the largest matching in any pair of disjoint matchings with the maximum total number of edges and the largest possible matching. Previously, it was shown that this ratio is between 4/5…

Combinatorics · Mathematics 2021-12-21 Zhengda Mo , Sam Qunell , Anush Tserunyan , Jenna Zomback

A graph is concave-round if its vertices can be circularly enumerated so that the closed neighbourhood of each vertex is an interval in the enumeration. In this work, we give a minimal forbidden induced subgraph characterization for the…

Combinatorics · Mathematics 2016-11-08 Martín D. Safe