# News & Events

## Seminar

Date/Time:
Thursday, July 5, 2018 - 16:00 to 17:00
Venue:
SMS Conference Hall
Speaker:
Affiliation:
IIT Guwahati
Title:
Connectedness and spectral properties of power graphs of finite groups

Abstract:- There are various graphs (e.g., intersection graph, commuting graph, prime graph, etc.) constructed from groups to study various properties of groups via graphs and vice versa. The power graph of a group $G$ is a graph with vertex set $G$ and two distinct vertices are adjacent if one is a power of the other. We begin this talk with a study on connectivity of power graphs of groups. Using the concept of quotient power graphs, we first present some characterizations of minimal separating sets of power graphs. Then we obtain some minimal separating sets of power graphs of finite cyclic groups. Consequently, we determine two upper bounds of vertex connectivity of power graphs of finite cyclic groups along with their exact value for some orders. We further provide some structural properties of power graphs of $p$-groups. Then we determine minimum degree of power graphs of finite cyclic groups (partially), dihedral groups, dicyclic groups and abelian $p$-groups. Moreover, we ascertain the equality of minimum degree with edge connectivity for power graphs of all finite groups, and then characterize its equality with vertex connectivity for power graphs of aforementioned groups. Proceeding further, we investigate Laplacian spectra of power graphs of finite cyclic groups, dicyclic groups and $p$-groups. We supply some characterizations for the equality of vertex connectivity and algebraic connectivity of power graphs of the above groups. Finally, we conclude with some unsolved problems concerning power graphs for future research.