Hostname: page-component-cd9895bd7-p9bg8 Total loading time: 0 Render date: 2024-12-25T02:34:59.862Z Has data issue: false hasContentIssue false

Effective irrationality measures for real and p-adic roots of rational numbers close to 1, with an application to parametric families of Thue–Mahler equations

Published online by Cambridge University Press:  27 September 2016

YANN BUGEAUD*
Affiliation:
Institut de Recherche Mathématique Avancée, UMR 7501, Université de Strasbourg et CNRS, 7, rue René Descartes, 67084 Strasbourg, France. e-mail: [email protected]

Abstract

We show how the theory of linear forms in two logarithms allows one to get very good effective irrationality measures for nth roots of rational numbers a/b, when a is very close to b. We give a p-adic analogue of this result under the assumption that a is p-adically very close to b, that is, that a large power of p divides a−b. As an application, we solve completely certain families of Thue–Mahler equations. Our results illustrate, admittedly in a very special situation, the strength of the known estimates for linear forms in logarithms.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 2016 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

[1] Bennett, M. A. Rational approximation to algebraic number of small height : the Diophantine equation |axn − byn | = 1. J. Reine Angew. Math. 535 (2001), 149.Google Scholar
[2] Bennett, M. A., Bugeaud, Y. and Mignotte, M. Perfect powers with few binary digits and related Diophantine problems, II. Math. Proc. Camb. Phil. Soc. 153 (2012), 525540.CrossRefGoogle Scholar
[3] Bennett, M. A., Bugeaud, Y. and Mignotte, M. Perfect powers with few binary digits and related Diophantine problems. Ann. Sc. Norm. Super. Pisa Cl. Sci. (5) 12 (2013), 941953.Google Scholar
[4] Bennett, M. A. and Dahmen, S. R. Klein forms and the generalised superelliptic equation. Ann. of Math. 177 (2013), 171239.Google Scholar
[5] Bennett, M. A. and de Weger, B. M. M.. On the Diophantine equation |axn − byn | = 1. Math. Comp. 67 (1998), 413438.CrossRefGoogle Scholar
[6] Bilu, Yu. et Bugeaud, Y.. Démonstration du théorème de Baker–Feldman via les formes linéaires en deux logarithmes. J. Théor. Nombres Bordeaux 12 (2000), 1323.CrossRefGoogle Scholar
[7] Bombieri, E. Effective Diophantine approximation on G m . Ann. Scuola Norm. Sup. Pisa Cl. Sci. 20 (1993), 6189.Google Scholar
[8] Bombieri, E. and Mueller, J. On effective measures of irrationality for $\root n \of{a/b}$ and related numbers. J. Reine Angew. Math. 342 (1983), 173196.Google Scholar
[9] Bugeaud, Y. Bornes effectives pour les solutions des équations en S-unités et des équations de Thue–Mahler. J. Number Theory 71 (1998), 227244.Google Scholar
[10] Bugeaud, Y. Linear forms in p-adic logarithms and the Diophantine equation (xn − 1)/(x − 1) = yq . Math. Proc. Camb. Phil. Soc. 127 (1999), 373381.CrossRefGoogle Scholar
[11] Bugeaud, Y. Linear forms in the logarithms of algebraic numbers close to 1 and applications to Diophantine equations. Proc. of the Number Theory conference. DION 2005, Mumbai (Narosa Publ. House, 2008), pp. 5976.Google Scholar
[12] Bugeaud, Y. Effective irrationality measures for quotients of logarithms of rational numbers. Hardy–Ramanujan J. 38 (2015), 4548.Google Scholar
[13] Bugeaud, Y. et Laurent, M.. Minoration effective de la distance p-adique entre puissances de nombres algébriques. J. Number Theory 61 (1996), 311342.Google Scholar
[14] Feldman, N. I. Une amélioration effective de l'exposant dans le théorème de Liouville (en russe). Izv. Akad. Nauk 35 (1971), 973990. Also: Math. USSR Izv. 5 (1971), 985–1002.Google Scholar
[15] Gouillon, N. Explicit lower bounds for linear forms in two logarithms . J. Théor. Nombres Bordeaux 18 (2006), 125146.Google Scholar
[16] Heuberger, C. Parametrised Thue equations – A survey. In: Proceedings of the RIMS symposium ‘Analytic Number Theory and Surrounding Areas’ (Kyoto, Oct. 18–22, 2004). RIMS Kôkyûroku, vol. 1511 (2006), pp. 82–91.Google Scholar
[17] Laurent, M., Mignotte, M. et Nesterenko, Y.. Formes linéaires en deux logarithmes et déterminants d'interpolation. J. Number Theory 55 (1995), 285321.Google Scholar
[18] Levesque, C. and Waldschmidt, M. Familles d'équations de Thue–Mahler n'ayant que des solutions triviales, Acta Arith. 155 (2012), 117138.CrossRefGoogle Scholar
[19] Mignotte, M. A note on the equation axn byn = c . Acta Arith. 75 (1996), 287295.Google Scholar
[20] Shorey, T. N. Linear forms in the logarithms of algebraic numbers with small coefficients I. J. Indian Math. Soc. (N. S.) 38 (1974), 271284.Google Scholar
[21] Thomas, E. Complete solutions to a family of cubic Diophantine equations. J. Number Theory 34 (1990), 235250.CrossRefGoogle Scholar
[22] Waldschmidt, M. Transcendence measures for exponentials and logarithms. J. Austral. Math. Soc. Ser. A 25 (1978), 445465.Google Scholar
[23] Waldschmidt, M. Diophantine Approximation on Linear Algebraic Groups. Transcendence Properties of the Exponential Function in Several Variables. Grundlehren Math. Wiss. 326 (Springer, Berlin, 2000).Google Scholar