• Kirill Alekseev, University of Oulou, May 2001.
• Valerio Capellini, Jagiellonian University Krakow, August 2006.
• Luiz Davidovich, Universidade Federal do Rio de Janeiro, 12-30 July 2006.
• Dominique Delande, Laboratoire Kastler Brossel de l'Universite Pierre et Marie Curie et de l'Ecole Normale Superieure, Paris, September-December 2000.
• Klaus Dietz, Universitaet Bonn, February-August 2002; August-September 2003.
• Shmuel Fishman, Technion, Haifa, January-February 2002; February 2003; 18-29 February 2004.
• Italo Guarneri, Universita degli Studi dell'Insubria, Como, 10-31 July 2004.
• Marek Kus, Polish Academy of Sciences, Warsaw, 18-29 August 2003.
• Abdelkader Makhoute, Universite Moulay Ismail, Meknes, July 2001.
• Rosario N. Mantegna, Universita di Palermo, June-July 2000.
• Christian Miniatura, Laboratoire Ondes et Desordre, Nice, July 2002.
• Florian Mintert, Harvard University, May 2005.
• Emil Persson, TU Wien, 15-26 September 2003.
• Peter Schlagheck, Universität Regensburg, 18-30 August 2003.
• Paulo Souto Ribeiro, Universidade Federal do Rio de Janeiro, 15-30 September 2006.
• Ken Taylor, The Queen's University of Belfast, 21 June to 28 July 2000; 21 January to 16 March 2001.
• Carlos Trallero-Giner, Universidad de Havanna, 15 May to 15 August 2007.
• Thomas Wellens, Laboratoire Kastler Brossel, Paris, 15-25 August 2003.