Recent Submissions

  • The automorphism group of a free-by-cyclic group in rank 2 

    Bogopolski, Oleg; Martino, Armando; Ventura Capell, Enric (2007-05)
    Article
    Open Access
    Let ¡ be an automorphism of a free group F 2 of rank 2 and let M ¡ = F 2 o ¡ Z be the corresponding mapping torus of ¡ . We prove that the group Out ( M ¡ ) is usually virtually cyclic. More- over, ...
  • Absolute-type shaft encoding using LFSR sequences with a prescribed length 

    Fuertes Armengol, José Mª; Balle Pigem, Borja de; Ventura Capell, Enric (2008-03-31)
    Article
    Open Access
    Maximal-length binary sequences have existed for a long time. They have many interesting properties, and one of them is that, when taken in blocks of n consecutive positions, they form 2n - 1 different codes in a closed ...
  • Absolute type shaft encoding using LFSR sequences with prescribed length 

    Fuertes Armengol, José Mª; Balle, Borja; Ventura Capell, Enric (2006-02)
    Article
    Open Access
    Maximal-length binary sequences have been known for a long time. They have many interesting properties, one of them is that when taken in blocks of n consecutive positions they form 2 n ° 1 diÆerent codes in a ...
  • Completion and decomposition of a clutter into representable matroids 

    Martí Farré, Jaume; Mier Vinué, Anna de (Elsevier, 2015-05-01)
    Article
    Restricted access - publisher's policy
    This paper deals with the question of completing a monotone increasing family of subsets Gamma of a finite set Omega to obtain the linearly dependent subsets of a family of vectors of a vector space. Specifically, we prove ...
  • Fixed subgroups are compressed in surface groups 

    Zhang, Qiang; Ventura Capell, Enric; Wu, Jianchun (2015-08-01)
    Article
    Restricted access - publisher's policy
    For a compact surface Sigma (orientable or not, and with boundary or not), we show that the fixed subgroup, Fix B, of any family B of endomorphisms of pi(1)(Sigma) is compressed in pi(1)(Sigma), i.e. rk(Fix B) <= rk(H) for ...
  • Extensions and presentations of transversal matroids 

    Bonin, Joseph; Mier Vinué, Anna de (2015-11-02)
    Article
    Restricted access - publisher's policy
    A transversal matroid MM can be represented by a collection of sets, called a presentation of MM, whose partial transversals are the independent sets of MM. Minimal presentations are those for which removing any element ...
  • On the diameter of random planar graphs 

    Chapuy, G.; Fusy, Éric; Giménez Llach, Omer; Noy Serrano, Marcos (2015)
    Article
    Open Access
    We show that the diameter diam(Gn) of a random labelled connected planar graph with n vertices is equal to n1/4+o(1) , in probability. More precisely, there exists a constant c > 0 such that {equation presented} for ˜ small ...
  • Group-theoretic orbit decidability 

    Ventura Capell, Enric (De Gruytr, 2014-12-01)
    Article
    Open Access
    A recent collection of papers in the last years have given a renovated interest to the notion of orbit decidability. This is a new quite general algorithmic notion, connecting with several classical results, and closely ...
  • An involution on bicubic maps and beta(0,1)-trees 

    Claesson, Anders; Kitaev, Sergey; Mier Vinué, Anna de (2015)
    Article
    Open Access
    Bicubic maps are in bijection with (0 ; 1)-trees. We introduce two new ways of decomposing (0 ; 1)-trees. Using this we de ne an endofunc- tion on (0 ; 1)-trees, and thus also on bicubic maps. We show that ...
  • Fixed subgroups in free groups: a survey 

    Ventura Capell, Enric (2002-03)
    Article
    Open Access
    This note is a survey of the main results known about fixed subgroups of endomorphisms of finitely generated free groups. A historic point of view is taken, emphasizing the evolution of this line of research, from ...

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