Between 2004 and 2006 Freidel has coauthored a series of papers on the Ponzano-Regge model, a spin foam model of 3-dimensional quantum gravity.[3] In 2007 he introduced, with Kirill Krasnov, a new spin foam model for 4-dimensional quantum gravity which has become known as the Freidel-Krasnov model.[1]
In 2011 Freidel published a paper with Giovanni Amelino-Camelia, Jerzy Kowalski-Glikman and Lee Smolin introducing the principle of relative locality, a proposed generalization of the principle of relativity in which different observers see different notions of spacetimes.[4] Between 2013 and 2015 he published a series of papers with Robert Leigh and Djordje Minic introducing a new formulation of string theory, metastring theory, which implements the notion of relative locality in a precise way and introduces a new notion of modular spacetime.[5]
