Laboratoire d'informatique de l'École polytechnique

Research at LIX

Research at LIX is organized around the notion of "research teams". One team combines researchers, teachers, PhD students, post doctoral fellows, etc. around a common scientific project. Many of the research teams are Common Research Teams (équipe-projet commune) with Inria.

The research teams can be broadly characterized along three thematic axes: algorithms, comibinatorics, and models; distributed systems and security; and symbolic calculation and proofs. The subdivision along these axes improves collaboration between teams and also improves the visibility of the research output of LIX.

Algorithms, combinatorics, and models

The algorithms, combinatorics, and models axis combines teams that are concerned with the study of non-computational objects using formal and algorithmic means.

  • The AlCo team researches constraint satisfaction problems and their complexity in various computational models, notably with regard to questions of logic and with probabilistic analysis.
  • The AMIB team is constructing an approach to structural biology which moves from combinatorial analysis of sequences to the three dimensional analysis of structure, with a particular interest in molecular interactions.
  • The COMBI team is interested in links between combinatorics and geometry and applies algorithmic and enumerative methods to problems arising in various contexts, from Statistical Physics to Data Compression to Enumerative Topology.
  • The SYSMO team is interested in modelling and optimization of complex industrial systems, which includes Big Data.
  • The STREAM team develops methods for extracting and representing structures in graphical data, in order to solve geometric modeling and computer animation problems in Computer Graphics.

Distributed Systems and Security

The teams of the distributed systems and security axis are interested in the guarantees of security properties, confidentiality properties, and the trustworthiness of centralized, distributed, and mobile systems.

  • the COMÈTE team defines models coming from process algebras and information theory in order to adapt them to the security and protection of privacy.
  • the GRACE team are experts of the mathematics and algorithms of cryptography and coding theory.
  • the NETWORKS team works on routing algorithms and protocols and on the architecture of networks, particularly very large networks, very dynamic networks, and constrained networks.

Symbolic Calculation and Proofs

The symbolic calculation and proofs axis combines four teams that have the general objective of improving our understanding of proofs and of the development of tools to aid in correct reasoning.

  • the MAX team focused on the efficiency and robustness of algorithms for symbolic calculation and utilities for algebra, differential calculus, and geometry.
  • the PARSIFAL team develops and exploits proof theory, a subject launched by Gentzen in the 1930s, and revitalized by Girard during the 1980s and 1990s. Their current applications are largely in the foundations of computer science.
  • The TYPICAL team develops and exploits type theory, a subject pioneered by De Bruijn and Martin-Löf during the 1930s, for which systems such as Coq have been developed and employed with success both in academic research and in the industry, as well as for educational purposes.
  • the COSYNUS team works on the semantics and static analysis of software systems, including distributed systems, hybrid systems, and cyber-physical systems.