Laurent Freidel, PhD L’ecole Normale Superieure de Lyon (1994), has made many notable contributions in the field of Quantum Gravity and joined Perimeter Institute as its ninth faculty member in September 2006. Freidel is a mathematical physicist with outstanding knowledge of a wide range of areas including integrable systems, topological field theories, 2d conformal field theory and QCD (Quantum Chromodynamics). He has authored or co-authored almost 40 publications, many of which are known among fellow researchers for offering particularly complete, detailed arguments. Freidel is also the author or co-author of several significant papers on spin foam models - higher-dimensional diagrams that operate as models of the quantum geometry of spacetime in loop quantum gravity. He also contributes to further research on the low energy limit of spin foam models including new proposed formulations and coupling to matter. Since receiving his PhD, Freidel has held positions as Penn State University and L’ecole Normale and has been a member of France’s Centre National de la Recherche Scientifique (CNRS) since 1995. Dr. Freidel is also the recipient of several awards including two ACI-Blanche grants in France. He has been a Long Term Visitor at Perimeter Institute since 2002 where, in addition to his scientific contributions, he has mentored several graduate students and postdoctoral researchers as well as co-organizing high-level international conferences in Quantum Gravity and mathematics.

Talks by Laurent Freidel

Quantum spaces are modular

Laurent Freidel Perimeter Institute for Theoretical Physics

In this talk I will review the construction of space starting purely from quantum mechanics and without assuming that the notion of space is attached to a preconceived notion of classical reality. I will show that if one start with the simplest notion of a quantum system encoded into the Heisenberg group algebra one naturally obtain a  notion of space that generalizes the usual notion of Euclidean space.

The relative locality of quantum spacetime

Laurent Freidel Perimeter Institute for Theoretical Physics

Should we revisit the concept of space solely based on quantum mechanics?

Do we need a radically new physical principle to address the problem of quantum gravity?

In this talk I will adress these questions. I will review what are the central challenges one faces when trying to understand the theory of quantum gravity from first principles and focus on the main one which is non-locality.

I will present a collection of results and ideas that have been developed in the recent years that provides a radical new perspective on these issues.

Metastring theory and Modular spacetime

Laurent Freidel Perimeter Institute for Theoretical Physics
In this talk I will review a recent reformulation of string theory which does not rely on an a priori space-time interpretation or a pre-assumption of locality and include form the onset stringy symmetries such as T-duality. I will explain how this resulting theory, called metastring, leads to formulation where the string is chiral and the target is phase space instead of space-time. I will discuss metastring theory on a flat background and summarize a variety of technical and interpretational ideas.