Page "Supergravity" Paragraph 10

* In 1978, Eugène Cremmer, Bernard Julia and Joël Scherk ( CJS ) found the classical action for an 11-dimensional supergravity theory.

This remains today the only known classical 11-dimensional theory with local supersymmetry and no fields of spin higher than two.

Other 11-dimensional theories are known that are quantum-mechanically inequivalent to the CJS theory, but classically equivalent ( that is, they reduce to the CJS theory when one imposes the classical equations of motion ).

For example, in the mid 1980s Bernard de Wit and Hermann Nicolai found an alternate theory in D = 11 Supergravity with Local SU ( 8 ) Invariance.

This theory, while not manifestly Lorentz-invariant, is in many ways superior to the CJS theory in that, for example, it dimensionally-reduces to the 4-dimensional theory without recourse to the classical equations of motion.