https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 On quotient digraphs and voltage digraphs https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30377 α . We prove that all the eigenvalues of ⌈ (including multiplicities) are, in addition, eigenvalues of ⌈α. This study is carried out by introducing several reduced matrix representations of ⌈α. As an example of our techniques, we study some basic properties of the Alegre digraph and its base.]]> Wed 11 Apr 2018 14:19:34 AEST ]]> From expanded digraphs to lifts of voltage digraphs and line digraphs https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30378 Wed 11 Apr 2018 12:26:06 AEST ]]> Multipartite Moore digraphs https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:9999 1 and diameter k = 2m are obtained. In the case δ = 1, which corresponds to almost Moore digraphs, a necessary condition in terms of the permutation cycle structure is derived. Additionally, we present some constructions of dense multipartite digraphs of diameter two that are vertex-transitive.]]> Sat 24 Mar 2018 08:12:15 AEDT ]]> An improved Moore bound and some new optimal families of mixed Abelian Cayley graphs https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:38494 Mon 11 Oct 2021 14:41:00 AEDT ]]> An algebraic approach to lifts of digraphs https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:36785 α of a voltage digraph, which has arcs weighted by the elements of a group. As a main result, when the involved group is Abelian, we completely determine the spectrum of Γα. As some examples of our technique, we study some basic properties of the Alegre digraph, and completely characterize the spectrum of a new family of digraphs, which contains the generalized Petersen graphs, and the Hoffman-Singleton graph.]]> Mon 06 Jul 2020 09:53:43 AEST ]]>