Louis Michel (physicist)

Louis Michel ( born May 4, 1923 in Roanne, near Lyon, † December 30 1999 in Bures -sur -Yvette ) was a French theoretical physicist.

Michel studied at the École Polytechnique in Paris and then conducted research in Manchester (via weak interaction ), Copenhagen and the Institute for Advanced Study in Princeton. He was then in France at the Universities of Lille, Paris ( Orsay ), the École polytechnique ( where he created a Center for Theoretical Physics, the Centre de physique théorique ) and then at the IHES in Bures -sur -Yvette, where he in 1962 and Professor permanent member and has also taught after his retirement until his death.

Michel described the Muonzerfall ( into an electron and two neutrinos ) by the introduced by him " Michel parameters". In the theory of strong interactions, he proved the conservation of G- parity, which forbids, for example, that an odd number of pions straight and vice versa merges number by the strong interaction in one. In 1959 he developed with Valentine Bargmann and Valentine Telegdi the Bargmann -Michel- Telegdi equation for the precession of the spins in the magnetic field. With Luigi Radicati he gave a geometric description of the adjoint representation of SU (3 ) ( octet) with applications to the quarks. In the 1980s, he also explored symmetries and symmetry breakings in solid state physics, where he used topological methods, and in the 1990s quasicrystals. As early as 1953 he described phase transitions as a symmetry-breaking phenomena.

He was 1978-1980 President of the French Physical Society and in different senior committee of the CNRS. He was an officer of the Legion of Honor and a member of the French Academy of Sciences ( 1979). He won the 1984 Wigner Medal. The IHES created a visiting professorship that bears his name. In 1966 he was invited speaker at the ICM in Moscow (Theory of groupes et particules element aires ).