A contribution to the theory of voltage graphs
Discrete Mathematics
Topological graph theory
Graph covering projections arising from finite vector spaces over finite fields
Discrete Mathematics
The MAGMA algebra system I: the user language
Journal of Symbolic Computation - Special issue on computational algebra and number theory: proceedings of the first MAGMA conference
On 2-arc-transitive covers of complete graphs
Journal of Combinatorial Theory Series B
Lifting graph automorphisms by voltage assignments
European Journal of Combinatorics
Coverings of Graphs and Maps, Orthogonality, and Eigenvectors
Journal of Algebraic Combinatorics: An International Journal
Homological methods in algebraic map theory
European Journal of Combinatorics
On Cubic Graphs Admitting an Edge-Transitive Solvable Group
Journal of Algebraic Combinatorics: An International Journal
s-Regular cubic graphs as coverings of the complete bipartite graph K3,3
Journal of Graph Theory
The edge-transitive but not vertex-transitive cubic graph on 112 vertices
Journal of Graph Theory
Edge-colourings of cubic graphs admitting a solvable vertex-transitive group of automorphisms
Journal of Combinatorial Theory Series B
On Cubic Graphs Admitting an Edge-Transitive Solvable Group
Journal of Algebraic Combinatorics: An International Journal
Classifying cubic symmetric graphs of order 8p or 8p2
European Journal of Combinatorics
A census of semisymmetric cubic graphs on up to 768 vertices
Journal of Algebraic Combinatorics: An International Journal
Invariant subspaces, duality, and covers of the Petersen graph
European Journal of Combinatorics
Cubic symmetric graphs of order a small number times a prime or a prime square
Journal of Combinatorial Theory Series B
Self-complementary two-graphs and almost self-complementary double covers
European Journal of Combinatorics
Constructing even radius tightly attached half-arc-transitive graphs of valency four
Journal of Algebraic Combinatorics: An International Journal
Journal of Combinatorial Theory Series B
Edge-transitive cyclic regular covers of the Möbius-Kantor graph
European Journal of Combinatorics
Arc-regular cubic graphs of order four times an odd integer
Journal of Algebraic Combinatorics: An International Journal
Efficient domination in cubic vertex-transitive graphs
European Journal of Combinatorics
Tetravalent vertex-transitive graphs of order 4p
Journal of Graph Theory
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Let \cal CG(X) be the set of all (equivalence classes of) regular covering projections of a given connected graph X along which a given group G ≤ Aut X of automorphisms lifts. There is a natural lattice structure on \cal CG(X), where ℘1 ≤ ℘2 whenever ℘2 factors through ℘1. The sublattice \cal CG(℘) of coverings which are below a given covering ℘ : X˜ → X naturally corresponds to a lattice \cal NG(℘) of certain subgroups of the group of covering transformations. In order to study this correspondence, some general theorems regarding morphisms and decomposition of regular covering projections are proved. All theorems are stated and proved combinatorially in terms of voltage assignments, in order to facilitate computation in concrete applications.For a given prime p, let \cal CGp(X) ≤ \cal CG(X) denote the sublattice of all regular covering projections with an elementary abelian p-group of covering transformations. There is an algorithm which explicitly constructs \cal CGp(X) in the sense that, for each member of \cal CGp(X), a concrete voltage assignment on X which determines this covering up to equivalence, is generated. The algorithm uses the well known algebraic tools for finding invariant subspaces of a given linear representation of a group. To illustrate the method two nontrival examples are included.