Now showing items 1-6 of 6

    • A lower bound for the size of a Minkowski sum of dilates 

      Hamidoune, Yahya Ould; Rué Perna, Juan José (2011-03-01)
      Article
      Open Access
      Let A be a finite non-empty set of integers. An asymptotic estimate of the size of the sum of several dilates was obtained by Bukh. The unique known exact bound concerns the sum |A + k·A|, where k is a prime and |A| is ...
    • On sums of dilates 

      Javier, Cilleruelo; Hamidoune, Yahya Ould; Serra Albó, Oriol (2009-10-05)
      Article
      Open Access
      For k prime and A a finite set of integers with |A| ≥ $3(k-1)^2$ (k-1)! we prove that |A+k·A| ≥ (k+1)|A| − ⌈k(k+2)/4⌉ where k·A = {ka:a∈A}. We also describe the sets for which equality holds.
    • On the tipology of vertex-transitive graphs 

      Hamidoune, Yahya Ould (2010-06-09)
      Audiovisual
      Open Access
    • Topology of Cayley graphs applied to inverse additive problems 

      Hamidoune, Yahya Ould (Iniciativa Digital Politècnica, 2011)
      Conference report
      Open Access
      We present the basic isopermetric structure theory, obtaining some new simplified proofs. Let 1 ≤ r ≤ k be integers. As an application, we obtain simple descriptions for the subsets S of an abelian group with |kS| ≤ ...
    • Vertex-transitive graphs that remain connected after failure of a vertex an its neighbors 

      Hamidoune, Yahya Ould; Lladó Sánchez, Ana M.; López Masip, Susana Clara (Wiley InterScience, 2010)
      Article
      Restricted access - publisher's policy
      A d-regular graph is said to be superconnected if any disconnecting subset with cardinality at most d is formed by the neighbors of some vertex. A superconnected graph that remains connected after the failure of a vertex ...
    • Vertex-Transitive Graphs That Remain Connected After Failure of a Vertex and Its Neighbors 

      Hamidoune, Yahya Ould; Lladó Sánchez, Ana M.; López Masip, Susana Clara (Wiley InterScience, 2011-06)
      Article
      Restricted access - publisher's policy
      A d-regular graph is said to be superconnected if any disconnecting subset with cardinality at most d is formed by the neighbors of some vertex. A superconnected graph that remains connected after the failure of a vertex ...