Wr. Greenberg et al., INVARIANT TORI AND HEISENBERG MATRIX-MECHANICS - A NEW WINDOW ON THE QUANTUM-CLASSICAL CORRESPONDENCE, Physical review letters, 75(7), 1995, pp. 1244-1247
Despite the seminal connection between classical multiply periodic mot
ion and Heisenberg matrix mechanics, we show that there are fundamenta
l, previously undisclosed aspects of this quantum-classical correspond
ence. These include a quantum variational principle that implies the c
lassical variational principle for invariant tori and the connection b
etween commutation relations and quantization of action variables. Pos
sible applications are described briefly.