Ara es mostren els items 1-12 de 12

    • A Note on sparse supersaturation and extremal results for linear homogeneous systems 

      Spiegel, Christoph (2017-08-25)
      Article
      Accés obert
      We study the thresholds for the property of containing a solution to a linear homogeneous system in random sets. We expand a previous sparse Sz\'emeredi-type result of Schacht to the broadest class of matrices possible. ...
    • A step beyond Freiman’s theorem for set addition modulo a prime 

      Candela Pokorna, Pablo; Serra Albó, Oriol; Spiegel, Christoph (2020-01-01)
      Article
      Accés obert
      Freiman’s 2.4-Theorem states that any set A¿Zp satisfying |2A|=2.4|A|-3 and |A|<p/35 can be covered by an arithmetic progression of length at most |2A|-|A|+1. A more general result of Green and Ruzsa implies that this ...
    • Additive structures and randomness in combinatorics 

      Spiegel, Christoph (Universitat Politècnica de Catalunya, 2020-07-03)
      Tesi
      Accés obert
      Arithmetic Combinatorics, Combinatorial Number Theory, Structural Additive Theory and Additive Number Theory are just some of the terms used to describe the vast field that sits at the intersection of Number Theory and ...
    • Additive volume of sets contained in few arithmetic progressions 

      Freiman, Gregory A.; Serra Albó, Oriol; Spiegel, Christoph (De Gruyter, 2019-03-06)
      Article
      Accés obert
      A conjecture of Freiman gives an exact formula for the largest volume of a finite set A of integers with given cardinality k=|A| and doubling T=|2A|. The formula is known to hold when T=3k-4, for some small range over 3k-4 ...
    • An Erdös–Fuchs theorem for ordered representation functions 

      Cao Labora, Gonzalo; Rué Perna, Juan José; Spiegel, Christoph (2020-10-28)
      Article
      Accés obert
      Letk=2 be a positive integer. We study concentration results for the ordered representationfunctionsr=k(A, n) = #{(a1= ··· =ak)¿ Ak:a1+···+ak=n}andr<k(A, n) = #{(a1<···<ak)¿ Ak:a1+···+ak=n}for any infinite set ...
    • 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 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 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 ...
    • 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. ...
    • The rado multiplicity problem in vector spaces over finite fields 

      Rué Perna, Juan José; Spiegel, Christoph (Muni press, 2023)
      Comunicació de congrés
      Accés obert
      We study an analogue of the Ramsey multiplicity problem for additive structures, establishing the minimum number of monochromatic $3$-APs in $3$-colorings of $\mathbb{F}_3^n$ and obtaining the first non-trivial lower bound ...
    • Threshold functions and Poisson convergence for systems of equations in random sets 

      Rué Perna, Juan José; Spiegel, Christoph; Zumalacárregui, Ana (2017-05-10)
      Article
      Accés obert
      We study threshold functions for the existence of solutions to linear systems of equations in random sets and present a unified framework which includes arithmetic progressions, sum-free sets, Bh[g]Bh[g]-sets and Hilbert ...