International Workshop on Dynamical Systems and Geometry in honor of Prof. Michel Herman

IMPA, Rio de Janeiro, April 9 – 12, 2001

This is a small but very special mathematical conference: it honors Michel Herman, a friend and a great mathematician, who passed away last November. In several ways he became much attached to IMPA, having attended since 1976 many of its conferences, particularly but not only in dynamical systems. He was also a common visitor and in fact he would spend two years with us, starting in early February 2001. One of his last beautiful gestures was to leave to IMPA’s library his more than two thousand mathematical books: a catalog is now being kindly prepared by the University of Paris – Jussieu. He also expressed the wish to have his ashes spread over the city of Rio de Janeiro and this shall take place in the end of the morning of April 10. Details shall be provided later.

Concerning the activities, there will be about six lectures a day from 9 to 12 April of 45 minutes each: three in the morning from 9 to 11:45 a.m. with 15 minutes break between them and three in the afternoon from 14:15 to 17:15 with half an hour break after the first lecture and 15 minutes break afterwards.


General Information

Please get in touch with a nearest Brazilian Consulate to find out whether you need a visa to come to Brazil. If you do, we recommend you apply for a tourist visa, which is usually simpler to obtain, and which is enough for this purpose.

No visa is required from citizens of South-American countries. Citizens from the European Union, as well as Western European countries like Switzerland or Norway do not need a visa either. On the other hand, US and Mexican citizens must apply for a visa to come to Brazil.

Information for visitors


Scientific Programme

April, 9 – Monday
Auditorium Ricardo Maסי
9:00 – 9:45 John Milnor
SUNY at Stony Brook
Dynamics and the Brain. Can dynamical methods help us to understand the functioning of the human brain? A naive report.
10:00 – 10:45 Christian Bonatti
Univ. Bourgogne
Recent results on robust transitivity and partial hyperbolicity
10:00 – 10:45 Enrique Pujals
The Dynamics of dominated decomposition
12:00 – 14:00 Lunch
14:15 – 15:00 Patrice Le Calvez
Univ. Paris Nord
Generalized Aubry-Mather sets for non twist maps of the annulus or the torus
15:00 – 15:30 Coffee Break
15:30 – 16:15 Harold Rosenberg
Univ. Paris VII
The unicity of the helicoid
16:30 – 17:15 Jean-Paul Thouvenot
Univ. Paris VII
Discontinuities of Lyapunov exponents and a theorem of M. Herman


April, 10 – Tuesday

Auditorium Ricardo Mañé
9:00 – 9:45 François Laudenbach
Univ. Nantes
About T*(Tn) and its Lagrangian submanifolds
10:00 – 10:45 Anatole Katok
Penn. State Univ.
Liouvillean phenomena in dynamics: Herman’s contribution and some new results
11:00 – 12:00 Ceremony
12:00 – 14:00 Lunch
14:15 – 15:00 Alain Chenciner
Univ. Paris VII
Are the masses of a choreography necessarily equal ?
15:00 – 15:30 Coffee Break
15:30 – 16:15 Ernst Heintze
Univ. Augsburg
Infinite dimensional symmetric spaces, submanifolds and Kac-Moody algebras
16:30 – 17:15 Viviane Baladi
Univ. Paris-Sud
Dynamical Determinants and Dominated Decomposition in Dimension 2


April, 11 – Wednesday
Auditorium Ricardo Maסי
9:00 – 9:45 Albert Fathi
ENS – Lyon
How Michel forced me to turn into PDE’s: Some local results on the Hamilton-Jacobi equation
10:00 – 10:45 Raphael Krikorian
ֹcole Polytechnique
About quasi-periodic cocycles
11:00 – 11:45 Jairo Bochi
Zero Lyapunov exponents
12:00 – 14:00 Lunch
14:15 – 15:00 J.- C. Yoccoz
Collטge de France
Rational p-adic dynamics, following J. RIVERA-LETELIER
15:00 – 15:30 Coffee Break
15:30 – 16:15 Maurםcio Peixoto
Focal stability of geodesics
16:30 – 17:15 Fraחois Ledrappier
ֹcole Polytechnique
Ergodic properties of some linear actions


April, 12 – Thursday
Auditorium Ricardo Maסי
9:00 – 9:45 John Mather
Princeton Univ.
Differentiability properties of the beta function
10:00 – 10:45 Raphael Douady
Circle diffeomorphisms and automorphic measures
11:00 – 11:45 Carlos G. Moreira
Statistical properties of unimodal maps
12:00 – 14:00 Lunch
14:15 – 15:00 Carlos Gutierrez
USP-Sדo Carlos
Injectivity of C1 maps R2 –> R2 at infinity and planar vector fields
15:00 – 15:30 Coffee Break
15:30 – 16:15 E. Zehnder
Pseudoholomorphic curves and dynamics in three dimensions
11:00 – 11:45 Hakan Eliasson
Royal Inst. Tech.
Almost reducibility of linear quasi-periodic systems



Baladi, Viviane Universitè Paris-Sud
Bassam, Fayad École Polytechnique
Bonatti, Christian Université de Bourgogne
Camacho, Cesar IMPA
Carneiro, Mario Jorge Univ. Fed. de Minas Gerais
Chenciner, Alain Univ. Paris VII
Dajczer, Marcos IMPA
De Melo, Welington IMPA
Diaz, Lorenzo PUC-RJ
Do Carmo, Manfredo IMPA
Douady, Raphael Ecole Normale Superieure-Cachan
Heintze, Ernst Univ. Augsburg
Faria, Edson IME/USP
Fathi, Albert Ecole Normale Sup. De Lyon
Flexor, Marguerite Univ. Paris Sud
Florit, Luis IMPA
Gutierrez, Carlos USP/São Carlos
Haefliger, Andre Univ. de Geneve
Hakan, Eliasson Royal Inst. Of Technology
Katok, Anatole Pennsylvania State University
Krikorian, Raphael École Polytechnique
Labarca, Rafael Univ. de Santiago de Chile
Laudenbach, François Univ. de Nantes
Le Calvez, Patrice Univ. Paris Nord
Ledrappier, François École Polytechnique
Lima, Elon Lages IMPA
Lins Neto, Alcides IMPA
Markarian, Roberto Univ. de la Republica
Mather, John Princeton University
Milnor, John SUNY at Stony Brook
Morales, Carlos UFRJ
Moreira, Carlos Gustavo IMPA
Oliveira, Fernando UFMG
Pacífico, Maria José UFRJ
Palis, Jacob IMPA
Peixoto, Maurício IMPA
Pujals, Enrique UFRJ
Ragazzo, Clodoaldo IME/USP
Rios Isabel UFF
Rocha, Luiz Fernando Univ. Fed. Rio Grande do Sul
Rosenberg, Harold Univ. Paris VII
Sotomayor, Jorge IME/USP
Thouvenot, Jean-Paul Univ. Paris VII
Vargas, Edson IME/USP
Viana, Marcelo IMPA
Yoccoz, Jean Christophe Collège de France
Zehnder, Eduard ETH – Zentrum


Department of Scientific Activities
IMPA, Estrada Dona Castorina 110
22460-320 Rio de Janeiro, Brazil
Fax: +55 (21) 529-5019