PROPERTIES OF NONLINEAR SCHRODINGER-EQUATIONS ASSOCIATED WITH DIFFEOMORPHISM GROUP-REPRESENTATIONS

The authors recently derived a family of nonlinear Schrodinger equations on R3 from fundamental considerations of generalized symmetry: ihBARpartial derivative(t)psi = -(hBAR2/2m)del2psi + F[psi, psiBAR]psi + ihBAR{del2psi + (\delpsi\2/\psi\2)psi}, where F is an arbitrary real functional and D a real, continuous quantum number. These equations, descriptive of a quantum mechanical current that includes a diffusive term, correspond to unitary representations of the group Diff (M) parametrized by D, where M = R3 is the physical space. In the present paper we explore the most natural ansatz for F, which is labelled by five real coefficients. We discuss the invariance properties, describe the stationary states and some non-stationary solutions, and determine the extra, dissipative terms that occur in the Ehrenfest theorem. We identify an interesting, Galilean-invariant subfamily whose properties we investigate, including the case where the dissipative terms vanish.