• Computing denumerants in numerical 3-semigroups 

      Aguiló Gost, Francisco de Asis L.; Llena, David (2018)
      Article
      Accés obert
      As far as we know, usual computer algebra packages can not compute denumerants for almost medium (about a hundred digits) or almost medium-large (about a thousand digits) input data in a reasonably time cost on an ordinary ...
    • Every integer can be written as a square plus a squarefree 

      Jiménez Urroz, Jorge (2022-09)
      Article
      Accés restringit per política de l'editorial
      In the paper we can prove that every integer can be written as the sum of two integers, one perfect square and one squarefree. We also establish the asymptotic formula for the number of representations of an integer in ...
    • On doubling and volume: chains 

      Freiman, Gregory A.; Serra Albó, Oriol (\Institute of Mathematics, Polish Academy of Sciences\, 2018-10-01)
      Article
      Accés obert
      The well-known Freiman–Ruzsa theorem provides a structural description of a set A of integers with |2A|=c|A| as a subset of a d–dimensional arithmetic progression P with |P|=c'|A|, where d and c' depend only on c. The ...
    • Revisiting Kneser’s theorem for field extensions 

      Bachoc, Christine; Serra Albó, Oriol; Zemor, Gilles (2017-05-31)
      Article
      Accés obert
      A Theorem of Hou, Leung and Xiang generalised Kneser’s addition Theorem to field extensions. This theorem was known to be valid only in separable extensions, and it was a conjecture of Hou that it should be valid for all ...
    • Structure of sets with small sumset and applications 

      Bardaji Goikoetxea, Itziar (Universitat Politècnica de Catalunya, 2008-10)
      Projecte Final de Màster Oficial
      Accés obert
      It was the main objective of this master thesis to determine the position of the holes for sets with small doubling. The answer to this question was given recently by Freiman and in here we generalize it to the case with ...
    • Towards 3n - 4 in groups of prime order 

      Lev, Vsevolod; Serra Albó, Oriol (2023-06-16)
      Article
      Accés obert
      We show that if A is a subset of a group of prime order p such that |2.Al < 2.7652|Al and 10 < |A| < 1.25 - 10-®p, then A is contained in an arithmetic progression with at most 2A - [Al + 1 terms, and 2.4 contains an ...