Signed graphs are graphs whose edges get a sign $+ 1$ or $-1$(the signature). Signed
graphs can be studied by means of graph matrices extended to signed graphs in a natural …

We develop the theory of equiangular lines in Euclidean spaces. Our focus is on the
question of when a Seidel matrix having precisely three distinct eigenvalues has a regular …

For $ e $ a positive integer, we find restrictions modulo $2^ e $ on the coefficients of the
characteristic polynomial $\chi _S (x) $ of a Seidel matrix $ S $. We show that, for a Seidel …

Let S (G) be the Seidel matrix of a graph G. The Seidel energy of G, denoted by ES (G), is
defined to be the sum of absolute values of all eigenvalues of the Seidel matrix S (G) of G. In …

A finite set of distinct vectors $\mathcal {X} $ in the $ d $-dimensional Euclidean space
$\mathbb {R}^ d $ is called an $ s $-distance set if the set of mutual distances between …

It is known that complete multipartite graphs are determined by their distance spectrum but
not by their adjacency spectrum. The Seidel spectrum of a graph G on more than one vertex …

The purpose of this paper is twofold. First, we determine the lower bound for the maximum
coherence between a pair of dual frames in C d and state conditions under which the lower …

On the Spectrum of Some Signed Complete and Complete Bipartite Graphs Page 1 Filomat
32:17 (2018), 5817–5826 https://doi.org/10.2298/FIL1817817A Published by Faculty of Sciences …

A Remark on a Construction of DS Asche | SpringerLink Skip to main content Advertisement
SpringerLink Log in Menu Find a journal Publish with us Search Cart 1.Home 2.Discrete & …

The Seidel matrix of a graph G with n vertices is defined as S (G)= JI-2 A (G), where A is its
adjacency matrix, J is the n× n square matrix whose all entries are 1 and I is the n× n identity …