Showing items related by title, author, creator and subject.

• On Vosperian and Superconnected Vertex-Transitive Digraphs 

  Hamidoune, Yahya Ould; Lladó, Anna; López Masip, Susana-Clara (Springer, 2013)

  We investigate the structure of a digraph having a transitive automorphism group where every cutset of minimal cardinality consists of all successors or all predecessors of some vertex. We give a complete characterization ...

• Large restricted sumsets in general Abelian groups 

  Hamidoune, Yahya Ould; López Masip, Susana-Clara; Plagne, Alain (Elsevier, 2013)

  Let A, B and S be subsets of a finite Abelian group G. The restricted sumset of A and B with respect to S is defined as A ∧S B = {a + b : a ∈ A, b ∈ B and a − b /∈ S}. Let LS = maxz∈G |{(x, y) : x, y ∈ G, x + y = z and x ...

• Every tree is a large subtree of a tree that decomposes Kn or Kn,n 

  Lladó, Anna; López Masip, Susana-Clara; Moragas, J. (Elsevier, 2010)

  Let T be a tree with m edges. A well-known conjecture of Ringel states that every tree T with m edges decomposes the complete graph K2m+1. Graham and H¨aggkvist conjectured that T also decomposes the complete bipartite ...