Ara es mostren els items 54-73 de 90

    • On a problem of Sárközy and Sós for multivariate linear forms 

      Rué Perna, Juan José; Spiegel, Christoph (2018-07-01)
      Article
      Accés obert
      We prove that for pairwise co-prime numbers k1,...,kd = 2 there does not exist any infinite set of positive integers A such that the representation function rA(n) = #{(a1,...,ad) ¿ Ad : k1a1 + ... + kdad = n} becomes ...
    • On a problem of Sárközy and Sós for multivariate linear forms 

      Rué Perna, Juan José; Spiegel, Christoph (2020-03-18)
      Article
      Accés obert
      We prove that for pairwise co-prime numbers k1,…,kd=2 there does not exist any infinite set of positive integers A such that the representation function rA(n)=# {(a1,…,ad)¿Ad:k1a1+¿ +kdad=n} becomes constant for n large ...
    • On a question of Sárkozy and Sós for bilinear forms 

      Cilleruelo, Javier; Rué Perna, Juan José (2009-02-02)
      Article
      Accés restringit per política de l'editorial
      We prove that if 2 ≤ k1 ≤ k2, then there is no infinite sequence $\emph{A}$ of positive integers such that the representation function r(n)=#{(a, a'): n=$k{_1}a$ + $k{_2}a'$, a,a' ∊ $\emph{A}$} is constant for n large ...
    • On Motzkin’s problem in the circle group 

      Candela Pokorna, Pablo; Catalá, Carlos; Rué Perna, Juan José; Serra Albó, Oriol (2021-09-01)
      Article
      Accés obert
      Given a subset D of the interval (0,1), if a Borel set A¿[0,1) contains no pair of elements whose difference modulo 1 is in D, then how large can the Lebesgue measure of A be? This is the analogue in the circle group of a ...
    • On polynomial representation functions for multivariate linear forms 

      Rué Perna, Juan José (2013-11-01)
      Article
      Accés obert
      Given an infinite sequence of positive integers A, we prove that for every nonnegative integer k the number of solutions of the equation n = a1 +· · ·+ak, a1, . . . , ak ¿ A, is not constant for n large enough. This result ...
    • On strong infinite Sidon and Bh sets and random sets of integers 

      Fabian, David; Rué Perna, Juan José; Spiegel, Christoph (2021-04-21)
      Article
      Accés obert
      A set of integers S ¿ N is an a–strong Sidon set if the pairwise sums of its elements are far apart by a certain measure depending on a, more specifically if (x + w) - (y + z) = max{xa, ya, za, wa} for every x, y, z, ...
    • On the error term of the logarithm of the lcm of quadratic sequences 

      Rué Perna, Juan José; Sarka, Paulius; Zumalacárregui, Ana (2013-01-09)
      Article
      Accés obert
      We study the logarithm of the least common multiple of the sequence of integers given by 12 + 1, 2 2 + 1, . . . , n2 + 1. Using a result of Homma [4] on the distribution of roots of quadratic polynomials modulo primes we ...
    • On the expected number of perfect matchings in cubic planar graphs 

      Noy Serrano, Marcos; Rué Perna, Juan José; Requile, Clement (2022-01-01)
      Article
      Accés obert
      A well-known conjecture by Lovász and Plummer from the 1970s asserted that a bridgeless cubic graph has exponentially many perfect matchings. It was solved in the affirmative by Esperet et al. (Adv. Math. 2011). On the ...
    • On the fractional Parts of a^n/n 

      Cilleruelo, Javier; Luca, Florian; Kumchev, Angel; Rué Perna, Juan José; Shparlinski, Igor (2013-09-30)
      Article
      Accés obert
      We give various results about the distribution of the sequence {a n/n}n=1 modulo 1, where a = 2 is a fixed integer. In particular, we find and infinite subsequence A such that {a n/n}n¿A is well distributed. Also we show ...
    • On the limiting distribution of the metric dimension for random forests 

      Rué Perna, Juan José; Mitsche, Dieter (2015-03-20)
      Article
      Accés obert
      The metric dimension of a graph G is the minimum size of a subset S of vertices of G such that all other vertices are uniquely determined by their distances to the vertices in S. In this paper we investigate the metric ...
    • On the number of nonzero digits of some integer sequences 

      Cilleruelo, Javier; Luca, Florián; Rué Perna, Juan José; Zumalacárregui, Ana (2012-06-05)
      Article
      Accés obert
      Let b = 2 be a fixed positive integer. We show for a wide variety of sequences {an}8n=1 that for most n the sum of the digits of an in base b is at least cb log n, where cb is a constant depending on b and on the sequence
    • On the optimality of the uniform random strategy 

      kush, Christopher; Rué Perna, Juan José; Spiegel, Christoph; Szabó, T. (2018-01-01)
      Article
      Accés restringit per política de l'editorial
      Biased Maker-Breaker games, introduced by Chvátal and Erdos, are central to the field of positional games and have deep connections to the theory of random structures. The main questions are to determine the smallest bias ...
    • Outerplanar obstructions for the vertex feedback set 

      Rué Perna, Juan José; Thilikos Touloupas, Dimitrios; Stavropoulos, Konstantinos (2012-07-02)
      Article
      Accés obert
      For k = 1, let Fk be the class of graphs that contains k vertices meeting all its cycles. The minor-obstruction set for Fk is the set obs(Fk) containing all minor-minimal graphs that do not belong to Fk. We denote by Yk ...
    • Pentagonal chains and annuli as models for designing nanostructures from cages 

      Rosenfeld, Vladimir; Dubrynin, Andrey; Oliva, Josep Ma; Rué Perna, Juan José (2016-03-01)
      Article
      Accés obert
      Carbon is the most versatile of chemical elements in combining with itself or other elements to form chains, rings, sheets, cages, and periodic 3D structures. One of the perspective trends for creating new molecules of ...
    • Product-free sets in the free group 

      Ortega Sánchez Colomer, Miquel; Rué Perna, Juan José; Serra Albó, Oriol (2023)
      Comunicació de congrés
      Accés obert
      We prove that product-free sets of the free group over a finite alphabet have max-imum density1/2with respect to the natural measure that assigns total weight oneto each set of irreducible words of a given length. This ...
    • Random cubic planar graphs revisited 

      Rué Perna, Juan José; Noy Serrano, Marcos; Requile, Clement (Elsevier, 2016)
      Altres
      Accés restringit per política de l'editorial
      The goal of our work is to analyze random cubic planar graphs according to the uniform distribution. More precisely, let G be the class of labelled cubic planar graphs and let gn be the number of graphs with n vertices. ...
    • Random cubic planar graphs revisited 

      Noy Serrano, Marcos; Requile, Clement; Rué Perna, Juan José (2016-10-18)
      Article
      Accés obert
      The goal of our work is to analyze random cubic planar graphs according to the uniform distribution. More precisely, let G be the class of labelled cubic planar graphs and let gn be the number of graphs with n vertices
    • Random cubic planar maps 

      Drmota, Michael; Noy Serrano, Marcos; Requile, Clement; Rué Perna, Juan José (2023-06-30)
      Article
      Accés obert
      We analyse uniform random cubic rooted planar maps and obtain limiting distributions for several parameters of interest. From the enumerative point of view, we present a unified approach for the enumeration of several ...
    • Random strategies are nearly optimal for generalized van der Waerden Games 

      Kusch, C.; Rué Perna, Juan José; Spiegel, Christoph; Szabó, T. (2017-08-01)
      Article
      Accés obert
      In a (1 : q) Maker-Breaker game, one of the central questions is to find (or at least estimate) the maximal value of q that allows Maker to win the game. Based on the ideas of Bednarska and Luczak [Bednarska, M., and T. ...
    • Spanning trees in random series-parallel graphs 

      Rué Perna, Juan José; Ehrenmüller, Julia (2016-04-01)
      Article
      Accés obert
      By means of analytic techniques we show that the expected number of spanning trees in a connected labelled series-parallel graph on n vertices chosen uniformly at random satisfies an estimate of the form s%-n(1 + o(1)), ...