IRIF is very pleased to host for three months Sergio Rajsbaum, full time Researcher at the Instituto de Matemáticas of the Universidad Nacional Autónoma de México. This collaboration focuses on the use of algebraic topology to study the complexity of distributed algorithms. Algebraic topology tools have been mainly used for shared memory models. The purpose of the visit is to extend this research to distributed memory models. Professor Rajsbaum is partially funded by an invitational program from École Polytechnique. Meet him in office 4028a.