On Q-derived polynomials

A Q-derived polynomial is a univariate polynomial, defined overthe rationals, with the property that its zeros, and those of allits derivatives are rational numbers. There is a conjecture thatsays that Q-derived polynomials of degree 4 with distinctroots for themselves and all their derivatives do not exist. Weare not aware of a deeper reason for their non-existence than thefact that so far no such polynomials have been found. In thispaper an outline is given of a direct approach to the problem ofconstructing polynomials with such properties. Although noQ-derived polynomial of degree 4 with distinct zeros foritself and all its derivatives was discovered, in the process wecame across two infinite families of elliptic curves withinteresting properties. Moreover, we construct some K-derivedpolynomials of degree 4 with distinct zeros for itself and allits derivatives for a few real quadratic number fields K ofsmall discriminant.Elliptic curve;Q-derived polynomial

Computing all integer solutions of a genus 1 equation

The Elliptic Logarithm Method has been applied with great successto the problem of computing all integer solutions of equations ofdegree 3 and 4 defining elliptic curves. We extend this methodto include any equation f(u,v)=0 that defines a curve of genus 1.Here f is a polynomial with integer coefficients and irreducible overthe algebraic closure of the rationals, but is otherwise of arbitrary shape and degree.We give a detailed description of the general features of our approach,and conclude with two rather unusual examples corresponding to equationsof degree 5 and degree 9.Elliptic curve;Elliptic logarithm;Dophantine equation

On Q-derived polynomials

A Q-derived polynomial is a univariate polynomial, defined over the rationals, with the property that its zeros, and those of all its derivatives are rational numbers. There is a conjecture that says that Q-derived polynomials of degree 4 with distinct roots for themselves and all their derivatives do not exist. We are not aware of a deeper reason for their non-existence than the fact that so far no such polynomials have been found. In this paper an outline is given of a direct approach to the problem of constructing polynomials with such properties. Although no Q-derived polynomial of degree 4 with distinct zeros for itself and all its derivatives was discovered, in the process we came across two infinite families of elliptic curves with interesting properties. Moreover, we construct some K-derived polynomials of degree 4 with distinct zeros for itself and all its derivatives for a few real quadratic number fields K of small discriminant

Computing all integer solutions of a genus 1 equation

The Elliptic Logarithm Method has been applied with great success to the problem of computing all integer solutions of equations of degree 3 and 4 defining elliptic curves. We extend this method to include any equation f(u,v)=0 that defines a curve of genus 1. Here f is a polynomial with integer coefficients and irreducible over the algebraic closure of the rationals, but is otherwise of arbitrary shape and degree. We give a detailed description of the general features of our approach, and conclude with two rather unusual examples corresponding to equations of degree 5 and degree 9

On Sums of Consecutive Squares

In this paper we consider the problem of characterizing those perfect squares that can be expressed as the sum of consecutive squares where the initial term in this sum is the square of k. This problem is intimately related to that of finding all integral points on elliptic curves belonging to a certain family which can be represented by a Weierstrass equation with parameter k. All curves in this family have positive rank, and for those of rank 1 a most likely candidate generator of infinite order can be explicitly given in terms of k. We conjecture that this point indeed generates the free part of the Mordell-Weil group, and give some heuristics to back this up. We also show that a point which is modulo torsion equal to a nontrivial multiple of this conjectured generator cannot be integral. For k in the range 1...100 the corresponding curves are closely examined, all integral points are determined and all solutions to the original problem are listed. It is worth mentioning that all curves of equal rank in this family can be treated more or less uniformly in terms of the parameter k. The reason for this lies in the fact that in Sinnou David's lower bound of linear forms in elliptic logarithms - which is an essential ingredient of our approach - the rank is the dominant factor. Also the extra computational effort that is needed for some values of k in order to determine the rank unconditionally and construct a set of generators for the Mordell-Weil group deserves special attention, as there are some unusual features

Elliptic curves of large rank and small conductor

For r=6,7,...,11 we find an elliptic curve E/Q of rank at least r and the smallest conductor known, improving on the previous records by factors ranging from 1.0136 (for r=6) to over 100 (for r=10 and r=11). We describe our search methods, and tabulate, for each r=5,6,...,11, the five curves of lowest conductor, and (except for r=11) also the five of lowest absolute discriminant, that we found.Comment: 16 pages, including tables and one .eps figure; to appear in the Proceedings of ANTS-6 (June 2004, Burlington, VT). Revised somewhat after comments by J.Silverman on the previous draft, and again to get the correct page break

Computing All Integer Solutions of a General Elliptic Equation

The Elliptic Logarithm Method has been applied with great success to the problem of computing all integer solutions of equations of degree 3 and 4 dening elliptic curves. We explore the possibility of extending this method to include any equation f(u; v) = 0, where f 2 Z[u;v] denes an irreducible curve of genus 1, independent of shape or degree of the polynomial f . We give a detailed description of the general features of our approach, putting forward along the way some claims (one of which conjectural) that are supported by the explicit examples added at the end.