Guillaume Hanrot

French version

I am a professor at ENS Lyon, and a member of the LIP lab.

I am a member of the Arenaire research group, which is also an INRIA project-team. I am also vice-president of INRIA's Evaluation Committee, and deputy director of the Computer Science Departement of ENS Lyon.

I have been involved in the development of the mpfr library and, in a more minor way, of the PARI system. Both of these are free software.

My scientific interests include algorithmic number theory and its applications. Among those, I have been working on problems in computer arithmetic (correct rounding of functions, polynomial and rational approximation and hard algorithmic problems in cryptology, eg lattice algorithmics which is my main center of interest those days.

Until September 2005, I was part-time associate professor at École polytechnique, and until 2009 I was an INRIA researcher at INRIA Nancy Grand Est, and team leader of the Cacao project-team.
Contact information

Guillaume HANROT
LIP / ENS-Lyon 46, allée d'Italie F-69364 LYON
e-mail : Guillaume.Hanrot@ens-lyon .fr
PGP/GnuPG public key
Phone : (+33) (0)4 72 72 87 59
Fax : (+33) (0)4 72 72 80 80

Publication list
  • Yuri Bilu, Guillaume Hanrot, Solving Thue equations of high degree, J. Number Theory 60 (1996), 373-392.
  • Yuri Bilu, Guillaume Hanrot, Solving Superelliptic Diophantine Equations by Baker's method, Compositio Math. 112 (1998), 273-312.
  • Yuri Bilu, Guillaume Hanrot, Thue equations with composite fields, Acta Arith. 88 (1999) no 4, 311-326.
  • Guillaume Hanrot, Solving Thue equations without the full unit group, Math. Comp. 69 (2000), 395-405.
  • Guillaume Hanrot, Natarajan Saradha, Tarlok Shorey, Almost perfect powers in consecutive integers, Acta Arith. 99 (2001) no 1-3, 13-25.
  • Yuri Bilu, Guillaume Hanrot, Paul Voutier, Existence of primitive divisors of Lucas and Lehmer numbers. J. Reine Angew. Math. 539 (2001), 75-122. Preliminary version
  • Yann Bugeaud, Guillaume Hanrot, Un nouveau critère pour l'équation de Catalan, Mathematika 47 (2000), 63-73. Preliminary version
  • Yann Bugeaud, Guillaume Hanrot, Maurice Mignotte, Sur l'équation diophantienne (x^n - 1)/(x - 1) = y^q, III. Proc. London Math. Soc. 84 (2002) no 1, 59-78. Preliminary version
  • Guillaume Hanrot, Joël Rivat, Gérald Tenenbaum, Paul Zimmermann, Density results on floating-point invertible numbers, Theoret. Comput. Sci., 291 (2004), 135-141.
  • Guillaume Hanrot, Michel Quercia, Paul Zimmermann, The Middle Product Algorithm, I. Speeding up the division and square root of power series, Appl. Alg. Eng. Comm. Comp. 14 (2004), 415-438. Preliminary version
  • Guillaume Hanrot, Paul Zimmermann, A note on Mulders' short product, J. Symb. Comput. 37 (2004), 391-401. Preliminary version
  • David Defour, Guillaume Hanrot, Vincent Lefèvre, Jean-Michel Muller, Nathalie Revol, and Paul Zimmermann. Proposal for a Standardization of Mathematical Function Implementation in Floating-Point Arithmetic, Numerical Algorithms, 37 (2004), 367-375. Preliminary version
  • Laurent Fousse, Guillaume Hanrot, Vincent Lefèvre, Patrick Pelissier, Paul Zimmermann, Multiple-Precision Floating-Point Computation With Well-Defined Semantics: The MPFR Library. ACM TOMS, 33 (2) (2007).
  • Guillaume Hanrot, Gérald Tenenbaum, Jie Wu, Moyenne de certaines fonctions arithmétiques sur les entiers friables, Proc. London Math. Soc. 96 (1) (2008), 107-135.
  • Guillaume Hanrot, Bruno Martin, Gérald Tenenbaum, Constantes de Turan-Kubilius friables : une étude expérimentale, Exp. Math. 19 (3) (2010), 345-361.

International Conferences
Book chapters
  • Guillaume Hanrot, Quelques idées sur l'algorithmique des équations diophantiennes. In N. Berline, A. Plagne, C. Sabbah (Éds.), Théorie algorithmique des nombres et équations diophantiennes, journées X-UPS 2005, Ellipses.
  • Yann Bugeaud, Guillaume Hanrot, Maurice Mignotte. Applications of Linear Forms in Logarithms. Chapter 12. Dans H. Cohen, Number theory: Analytic and Modern Methods, Springer-Verlag Graduate Texts in Mathematics 240, to appear.
  • Guillaume Hanrot, LLL: a tool for effective diophantine approximation. Dans P. Q. Nguyen, B. Vallée (Eds.), The LLL Algorithm: Survey and Applications, Springer-Verlag, Series Information Security and Cryptography (2009), pp. 215-264.

Proceedings volume edited.
Manuscripts and lecture notes
Last update on Nov. 22, 2010.