Jean Ecalle Chercheur au CNRS (D.R.) Equipe d'Analyse Harmonique Mathématiques, Bât. 425 Université Paris-Sud 91405 Orsay Cedex - France  Email : Jean.Ecalle@math.u-psud.fr  Office room : 152  Phone : 33 (0) 1 69 15 57 51 Main research themes. Main publications. Guided tour through resurgence theory. Updates on the flexion structure and ARI-GARI. Former PhD students.