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Power-free values, large deviations, and integer points on irrational curves

Harald A. Helfgott (2007)

Journal de Théorie des Nombres de Bordeaux

Let f [ x ] be a polynomial of degree d 3 without roots of multiplicity d or ( d - 1 ) . Erdős conjectured that, if f satisfies the necessary local conditions, then f ( p ) is free of ( d - 1 ) th powers for infinitely many primes p . This is proved here for all f with sufficiently high entropy.The proof serves to demonstrate two innovations: a strong repulsion principle for integer points on curves of positive genus, and a number-theoretical analogue of Sanov’s theorem from the theory of large deviations.

Random Thue and Fermat equations

Rainer Dietmann, Oscar Marmon (2015)

Acta Arithmetica

We consider Thue equations of the form a x k + b y k = 1 , and assuming the truth of the abc-conjecture, we show that almost all locally soluble Thue equations of degree at least three violate the Hasse principle. A similar conclusion holds true for Fermat equations a x k + b y k + c z k = 0 of degree at least six.

Ranks of quadratic twists of elliptic curves

Mark Watkins, Stephen Donnelly, Noam D. Elkies, Tom Fisher, Andrew Granville, Nicholas F. Rogers (2014)

Publications mathématiques de Besançon

We report on a large-scale project to investigate the ranks of elliptic curves in a quadratic twist family, focussing on the congruent number curve. Our methods to exclude candidate curves include 2-Selmer, 4-Selmer, and 8-Selmer tests, the use of the Guinand-Weil explicit formula, and even 3-descent in a couple of cases. We find that rank 6 quadratic twists are reasonably common (though still quite difficult to find), while rank 7 twists seem much more rare. We also describe our inability to find...

Résultats élémentaires sur certaines équations diophantiennes

Pierre Samuel (2002)

Journal de théorie des nombres de Bordeaux

Dans des travaux profonds, W. Ljunggren a montré que, pour a > 0 donné, les équations diophantiennes x 4 - a y 2 = 1 and x 2 - a y 4 = 1 ont au plus 1 ou 2 solutions non triviales. Par des méthodes élémentaires, je réponds ici à la question : pour quelles valeurs de a , premières ou analogues, ont-elles des solutions non-triviales ?

Searching for Diophantine quintuples

Mihai Cipu, Tim Trudgian (2016)

Acta Arithmetica

We consider Diophantine quintuples a, b, c, d, e. These are sets of positive integers, the product of any two elements of which is one less than a perfect square. It is conjectured that there are no Diophantine quintuples; we improve on current estimates to show that there are at most 5 . 441 · 10 26 Diophantine quintuples.

Siegel’s theorem and the Shafarevich conjecture

Aaron Levin (2012)

Journal de Théorie des Nombres de Bordeaux

It is known that in the case of hyperelliptic curves the Shafarevich conjecture can be made effective, i.e., for any number field k and any finite set of places S of k , one can effectively compute the set of isomorphism classes of hyperelliptic curves over k with good reduction outside S . We show here that an extension of this result to an effective Shafarevich conjecture for Jacobians of hyperelliptic curves of genus g would imply an effective version of Siegel’s theorem for integral points on...

Smooth solutions to the a b c equation: the x y z Conjecture

Jeffrey C. Lagarias, Kannan Soundararajan (2011)

Journal de Théorie des Nombres de Bordeaux

This paper studies integer solutions to the a b c equation A + B + C = 0 in which none of A , B , C have a large prime factor. We set H ( A , B , C ) = max ( | A | , | B | , | C | ) , and consider primitive solutions ( gcd ( A , B , C ) = 1 ) having no prime factor larger than ( log H ( A , B , C ) ) κ , for a given finite κ . We show that the a b c Conjecture implies that for any fixed κ < 1 the equation has only finitely many primitive solutions. We also discuss a conditional result, showing that the Generalized Riemann hypothesis (GRH) implies that for any fixed κ > 8 the a b c equation has infinitely many primitive solutions....

The circle method and pairs of quadratic forms

Henryk Iwaniec, Ritabrata Munshi (2010)

Journal de Théorie des Nombres de Bordeaux

We give non-trivial upper bounds for the number of integral solutions, of given size, of a system of two quadratic form equations in five variables.

The intersection of a curve with algebraic subgroups in a product of elliptic curves

Evelina Viada (2003)

Annali della Scuola Normale Superiore di Pisa - Classe di Scienze

We consider an irreducible curve 𝒞 in E n , where E is an elliptic curve and 𝒞 and E are both defined over ¯ . Assuming that 𝒞 is not contained in any translate of a proper algebraic subgroup of E n , we show that the points of the union 𝒞 A ( ¯ ) , where A ranges over all proper algebraic subgroups of E n , form a set of bounded canonical height. Furthermore, if E has Complex Multiplication then the set 𝒞 A ( ¯ ) , for A ranging over all algebraic subgroups of E n of codimension at least 2 , is finite. If E has no Complex Multiplication...

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