Electronic Journal of Graph Theory and Applications (EJGTA)
Vol 4, No 1 (2016): Electronic Journal of Graph Theory and Applications

A graph theoretical analysis of the number of edges in k-dense graphs

Linda Eroh (Department of Mathematics, University of Wisconsin-Oskhosh, Oshkosh, WI, USA)
Henry Escuadro (Department of Mathematics, Juniata College, Huntingdon, PA, USA)
Ralucca Gera (Department of Applied Mathematics, Naval Postgraduate School, Monterey, CA, USA)
Samuel Prahlow (Department of Mathematics and Statistics, Valparaiso University, Valparaiso, IN, USA)
Karl Schmitt (Department of Mathematics and Statistics, Department of Computer and Information Sciences, Valparaiso University, Valparaiso, IN, USA)



Article Info

Publish Date
11 Apr 2016

Abstract

Due to the increasing discovery and implementation of networks within all disciplines of life, the study of subgraph connectivity has become increasingly important. Motivated by the idea of community (or subgraph) detection within a network/graph, we focused on finding characterizations of k-dense communities. For each edge $uv\in E(G)$, the {\bf edge multiplicity} of $uv$ in $G$ is given by $m_G(uv)=|N_{G}(u)\cap N_{G}(v)|.$ For an integer $k$ with $k\ge 2$, a {\bf $\boldsymbol{k}$-dense community} of a graph $G$, denoted by $DC_k(G)$, is a maximal connected subgraph of $G$ induced by the vertex set$V_{DC_k(G)} = \{v\in V(G) : \exists u\in V(G)\ {\rm such\ that\ } uv\in E(G)\ {\rm and\ } m_{DC_{k(G)}}(uv)\ge k-2\}.$In this research, we characterize which graphs are $k$-dense but not $(k+1)$-dense for some values of $k$ and study the minimum and maximum number of edges such graphs can have. A better understanding of $k$-dense sub-graphs (or communities) helps in the study of the connectivity of large complex graphs (or networks) in the real world.

Copyrights © 2016






Journal Info

Abbrev

ejgta

Publisher

Subject

Electrical & Electronics Engineering

Description

The Electronic Journal of Graph Theory and Applications (EJGTA) is a refereed journal devoted to all areas of modern graph theory together with applications to other fields of mathematics, computer science and other sciences. The journal is published by the Indonesian Combinatorial Society ...