Postdoctoral positions @ Ecole Polytechnique. Description: The combinatorics team of the CS lab of the french Ecole Polytechnique seeks postdoctoral researchers for a research project on combinatorial approaches to the study of embedded graphs and discrete surfaces, headed by Pr. Gilles Schaeffer. The Ecole Polytechnique is located in Palaiseau, in the Paris area. The researchers will contribute to the research of a team of computer scientists and mathematicans working in combinatorics and algorithmics within the 2008-2013 European Research Council (ERC) funded project "ExploreMaps: Combinatorial methods, from enumerative topology to random discrete structures and compact data representations" http://www.lix.polytechnique.fr/~schaeffe/ExploreMaps/ The appointments are full time research positions with a net salary determined by CNRS salary tables, around 2000EUR/month. The holders will in addition benefit from the project funds for e.g. conference participations. We expect to fill one 12 month position every academic year of the project, although other arrangements are possible. Requirements: PhD defended before starting date, not more than 3 years ago. Expertise in at least one of the following areas: enumerative combinatorics / discrete probability / random combinatorial structures / combinatorial maps / embedded graphs / succinct data structures / graph algorithms / mesh compression. Good knowledge of english or french. Applicants that are interested in a position for the academic year 2011-2012 should preferably send their CV and a short motivation letter to Gilles.Schaeffer@lix.polytechnique.fr by april 1, 2011. They should also arrange for two letters of recommandations to be sent to the same address.