The Experts below are selected from a list of 5394 Experts worldwide ranked by ideXlab platform

Michel Zoeteman - One of the best experts on this subject based on the ideXlab platform.

Enrique Gonzalezjimenez - One of the best experts on this subject based on the ideXlab platform.

  • five squares in Arithmetic Progression over quadratic fields
    Revista Matematica Iberoamericana, 2013
    Co-Authors: Enrique Gonzalezjimenez, Xavier Xarles
    Abstract:

    We give several criteria to show over which quadratic number fields Q(sqrt{D}) there should exists a non-constant Arithmetic Progressions of five squares. This is done by translating the problem to determining when some genus five curves C_D defined over Q have rational points, and then using a Mordell-Weil sieve argument among others. Using a elliptic Chabauty-like method, we prove that the only non-constant Arithmetic Progressions of five squares over Q(sqrt{409}), up to equivalence, is 7^2, 13^2, 17^2, 409, 23^2. Furthermore, we give an algorithm that allow to construct all the non-constant Arithmetic Progressions of five squares over all quadratic fields. Finally, we state several problems and conjectures related to this problem.

  • markoff rosenberger triples in Arithmetic Progression
    Journal of Symbolic Computation, 2013
    Co-Authors: Enrique Gonzalezjimenez, Jose M Tornero
    Abstract:

    We study the solutions of the Rosenberg-Markoff equation ax^2+by^2+cz^2=dxyz (a generalization of the well-known Markoff equation). We specifically focus on looking for solutions in Arithmetic Progression that lie in the ring of integers of a number field. With the help of previous work by Alvanos and Poulakis, we give a complete decision algorithm, which allows us to prove finiteness results concerning these particular solutions. Finally, some extensive computations are presented regarding two particular cases: the generalized Markoff equation x^2+y^2+z^2=dxyz over quadratic fields and the classic Markoff equation x^2+y^2+z^2=3xyz over an arbitrary number field.

  • three cubes in Arithmetic Progression over quadratic fields
    Archiv der Mathematik, 2010
    Co-Authors: Enrique Gonzalezjimenez
    Abstract:

    We study the problem of the existence of Arithmetic Progressions of three cubes over quadratic number fields \({{\mathbb{Q}(\sqrt{D})}}\), where D is a squarefree integer. For this purpose, we give a characterization in terms of \({{\mathbb{Q}(\sqrt{D})}}\)-rational points on the elliptic curve E : y2 = x3 − 27. We compute the torsion subgroup of the Mordell–Weil group of this elliptic curve over \({{\mathbb{Q}(\sqrt{D})}}\) and we give an explicit answer, in terms of D, to the finiteness of the free part of \({E({\mathbb{Q}(\sqrt{D})})}\) for some cases. We translate this task to computing whether the rank of the quadratic D-twist of the modular curve X0(36) is zero or not.

  • three cubes in Arithmetic Progression over quadratic fields
    arXiv: Number Theory, 2009
    Co-Authors: Enrique Gonzalezjimenez
    Abstract:

    We study the problem of the existence of Arithmetic Progressions of three cubes over quadratic number fields Q(sqrt(D)), where D is a squarefree integer. For this purpose, we give a characterization in terms of Q(sqrt(D))-rational points on the elliptic curve E:y^2=x^3-27. We compute the torsion subgroup of the Mordell-Weil group of this elliptic curve over Q(sqrt(D)) and we give partial answers to the finiteness of the free part of E(Q(sqrt(D))). This last task will be translated to compute if the rank of the quadratic D-twist of the modular curve X_0(36) is zero or not.

Xavier Xarles - One of the best experts on this subject based on the ideXlab platform.

  • five squares in Arithmetic Progression over quadratic fields
    Revista Matematica Iberoamericana, 2013
    Co-Authors: Enrique Gonzalezjimenez, Xavier Xarles
    Abstract:

    We give several criteria to show over which quadratic number fields Q(sqrt{D}) there should exists a non-constant Arithmetic Progressions of five squares. This is done by translating the problem to determining when some genus five curves C_D defined over Q have rational points, and then using a Mordell-Weil sieve argument among others. Using a elliptic Chabauty-like method, we prove that the only non-constant Arithmetic Progressions of five squares over Q(sqrt{409}), up to equivalence, is 7^2, 13^2, 17^2, 409, 23^2. Furthermore, we give an algorithm that allow to construct all the non-constant Arithmetic Progressions of five squares over all quadratic fields. Finally, we state several problems and conjectures related to this problem.

  • squares in Arithmetic Progression over number fields
    Journal of Number Theory, 2012
    Co-Authors: Xavier Xarles
    Abstract:

    Abstract We show that there exists an upper bound for the number of squares in Arithmetic Progression over a number field that depends only on the degree of the field. We show that this bound is 5 for quadratic fields, and also that the result generalizes to k -powers for integers k > 1 .

  • squares in Arithmetic Progression over number fields
    arXiv: Algebraic Geometry, 2009
    Co-Authors: Xavier Xarles
    Abstract:

    We show that there exists an upper bound for the number of squares in Arithmetic Progression over a number field that depends only on the degree of the field. We show that this bound is 5 for quadratic fields, and also that the result generalizes to $k$-powers for $k>1$.

Alexandru Zaharescu - One of the best experts on this subject based on the ideXlab platform.

  • partitions into k th powers of terms in an Arithmetic Progression
    Mathematische Zeitschrift, 2018
    Co-Authors: Bruce C Berndt, Alexandru Zaharescu, Amita Malik
    Abstract:

    G. H. Hardy and S. Ramanujan established an asymptotic formula for the number of unrestricted partitions of a positive integer, and claimed a similar asymptotic formula for the number of partitions into perfect kth powers, which was later proved by E. M. Wright. Recently, R. C. Vaughan provided a simpler asymptotic formula in the case $$k=2$$ . In this paper, we consider partitions into parts from a specific set $$A_k(a_0,b_0) :=\left\{ m^k : m \in \mathbb {N} , m \equiv a_0 \,(\text {mod}\,b_0) \right\} $$ , for fixed positive integers k, $$a_0,$$ and $$b_0$$ . We give an asymptotic formula for the number of such partitions, thus generalizing the results of Wright and Vaughan. Moreover, we prove that the number of such partitions is even (odd) infinitely often, which generalizes O. Kolberg’s theorem for the ordinary partition function p(n).

  • Sums of Kloosterman sums over primes in an Arithmetic Progression
    arXiv: Number Theory, 2018
    Co-Authors: Alexander Dunn, Alexandru Zaharescu
    Abstract:

    For $q$ prime, $X \geq 1$ and coprime $u,v \in \mathbb{N}$ we estimate the sums \begin{equation*} \sum_{\substack{p \leq X \substack p \equiv u \hspace{-0.25cm} \mod{v} p \text{ prime}}} \text{Kl}_2(p;q), \end{equation*} where $\text{Kl}_2(p;q)$ denotes a normalised Kloosterman sum with modulus $q$. This is a sparse analogue of a recent theorem due to Blomer, Fouvry, Kowalski, Michel and Mili\'cevi\'c showing cancellation amongst sums of Kloosterman sums over primes in short intervals. We use an optimisation argument inspired by Fouvry, Kowalski and Michel. Our argument compares three different bounds for bilinear forms involving Kloosterman sums. The first input in this method is a bilinear bound we prove using uniform asymptotics for oscillatory integrals due to Petrow, Kiral and Young. In contrast with the case when the sum runs over all primes, we exploit cancellation over a sum of stationary phase integrals that result from a Voronoi type summation. The second and third inputs are deep bilinear bounds for Kloosterman sums due to Fouvry-Kowalski-Michel and Kowalski-Michel-Sawin.

  • on the farey fractions with denominators in Arithmetic Progression
    Journal of Integer Sequences, 2006
    Co-Authors: Cristian Cobeli, Alexandru Zaharescu
    Abstract:

    Let F Q be the set of Farey fractions of order Q. Given the integers d ≥ 2 and 0 ≤ c ≤ d − 1, let F Q (c, d) be the subset of F Q of those fractions whose denominators are ≡ c (mod d), arranged in ascending order. The problem we address here is to show that as Q → ∞, there exists a limit probability measuring the distribution of s-tuples of consecutive denominators of fractions in F Q (c, d). This shows that the clusters of points (q0/Q, q1/Q, . . . , qs/Q) ∈ [0, 1] s+1 , where q0, q1, . . . , qs are consecutive denominators of members of F Q produce a limit set, denoted by D(c, d). The shape and the structure of this set are presented in several particular cases.

  • On the Farey fractions with denominators in Arithmetic Progression
    arXiv: Number Theory, 2005
    Co-Authors: Cristian Cobeli, Alexandru Zaharescu
    Abstract:

    Let $F_Q$ be the set of Farey fractions of order $Q$. Given the integers $\d\ge 2$ and $0\le \c \le \d-1$, let $F_Q(c,d)$ be the subset of $F_Q$ of those fractions whose denominators are $\equiv c \pmod d$, arranged in ascending order. The problem we address here is to show that as $Q\to\infty$, there exists a limit probability measuring the distribution of $s$-tuples of consecutive denominators of fractions in $F_Q(c,d)$. This shows that the clusters of points $(q_0/Q,q_1/Q,...,q_s/Q)\in[0,1]^{s+1}$, where $q_0,q_1,...,q_s$ are consecutive denominators of members of $F_Q$ produce a limit set, denoted by $D(c,d)$. The shape and the structure of this set are presented in several particular cases.

Carlo Sanna - One of the best experts on this subject based on the ideXlab platform.