6 research outputs found
Integral Cayley graphs and groups
We solve two open problems regarding the classification of certain classes of
Cayley graphs with integer eigenvalues. We first classify all finite groups
that have a "non-trivial" Cayley graph with integer eigenvalues, thus solving a
problem proposed by Abdollahi and Jazaeri. The notion of Cayley integral groups
was introduced by Klotz and Sander. These are groups for which every Cayley
graph has only integer eigenvalues. In the second part of the paper, all Cayley
integral groups are determined.Comment: Submitted June 18 to SIAM J. Discrete Mat
On finite groups all of whose cubic Cayley graphs are integral
For any positive integer , let denote the set of finite
groups such that all Cayley graphs are integral whenever
. Estlyi and Kovcs \cite{EK14}
classified for each . In this paper, we characterize
the finite groups each of whose cubic Cayley graphs is integral. Moreover, the
class is characterized. As an application, the classification
of is obtained again, where .Comment: 11 pages, accepted by Journal of Algebra and its Applications on June
201
Algebraic degrees of -Cayley digraphs over abelian groups
A digraph is called an -Cayley digraph if its automorphism group has an
-orbit semiregular subgroup. We determine the splitting fields of -Cayley
digraphs over abelian groups and compute a bound on their algebraic degrees,
before applying our results on Cayley digraphs over non-abelian groups