3 papers
math.CO2021
On signed graphs with at most two eigenvalues unequal to
Willem H. Haemers, Hatice Topcu
We present the first steps towards the determination of the signed graphs for which the adjacency matrix has all but at most two eigenvalues equal to 1 or -1. Here we deal with the…
math.CO2018
On the spectral characterization of mixed extensions of
Willem H. Haemers, Sezer Sorgun, Hatice Topcu
A mixed extension of a graph is a graph obtained from by replacing each vertex of by a clique or a coclique, whilst two vertices in corresponding to distinct ve…
math.CO2015
On the spectral characterization of Kite graphs
Sezer Sorgun, Hatice Topcu
The \textit{Kite graph}, denoted by is obtained by appending a complete graph to a pendant vertex of a path . In this paper, firstly we show that no two…