Expander Graphs – A Study

Expander graphs are highly connected graphs that have numerous applications in statistical physics, pure mathematics and in computer science. The increased connectivity in expanders are useful to model connections between interconnecting systems which can be considered as a graph composed of particles as vertices and edges represent interactions. This paper focuses on the fascinating and highly active area of research on expander graphs. In this article, different classes of expander graphs such as Schreier graphs, Ramanujan graphs and Lp-expanders are categorized and various constructions of an explicit family of expanders are explored. Based on their construction the chromatic number of these are graphs are obtained.