Panoramas et synthèses

The series Panoramas & Synthèses publishes, in English or in French, monographs whose main goal is to provide a synthetic viewpoint on a given mathematical topic. The style of the publications is clear and comprehensive. The contributions sometimes come from meetings organized in the same spirit, but the origin can be a more personal initiative. The authors attempt to focus on the main ideas, intuitions and guidelines of a mathematical field, and to give a sketch of the most recent developments of the subject. The scope of the series covers all mathematical topics, including interactions with other fields; some well-known references have already been published in this collection. The texts are aimed at mathematicians who are not necessarily specialised in the presented subject. Therefore they are particularly recommended to postgraduate students.