We apply stochastic quantization to a system of N interacting identical bosons in an external potential phi, by means of a general stationary- action principle. The collective motion is described in terms of a Markovian diffusion on R-3N, with joint density rho. and entangled current velocity field V, in principle of nongradient form, related to one another by the continuity equation. Dynamical equations relax to those of canonical quantization, in some analogy with Parisi-Wu stochastic quantization. Thanks to the identity of particles, the one-particle marginal densities., in the physical space R-3, are all the same and it is possible to give, under mild conditions, a natural definition of the single-particle current velocity, which is related to. by the continuity equation in R-3. The motion of single particles in the physical space comes to be described in terms of a non-Markovian three-dimensional diffusion with common density. and, at least at dynamical equilibrium, common current velocity v. The three-dimensional drift is perturbed by zero-mean terms depending on the whole configuration of the N-boson interacting system. Finally, we discuss in detail under which conditions the one- particle dynamical equations, which in their general form allow rotational perturbations, can be particularized, up to a change of variables, to the Gross-Pitaevskii equations.

Stochastic quantization for a system of N identical interacting Bose particles

MORATO, Laura Maria;
2007-01-01

Abstract

We apply stochastic quantization to a system of N interacting identical bosons in an external potential phi, by means of a general stationary- action principle. The collective motion is described in terms of a Markovian diffusion on R-3N, with joint density rho. and entangled current velocity field V, in principle of nongradient form, related to one another by the continuity equation. Dynamical equations relax to those of canonical quantization, in some analogy with Parisi-Wu stochastic quantization. Thanks to the identity of particles, the one-particle marginal densities., in the physical space R-3, are all the same and it is possible to give, under mild conditions, a natural definition of the single-particle current velocity, which is related to. by the continuity equation in R-3. The motion of single particles in the physical space comes to be described in terms of a non-Markovian three-dimensional diffusion with common density. and, at least at dynamical equilibrium, common current velocity v. The three-dimensional drift is perturbed by zero-mean terms depending on the whole configuration of the N-boson interacting system. Finally, we discuss in detail under which conditions the one- particle dynamical equations, which in their general form allow rotational perturbations, can be particularized, up to a change of variables, to the Gross-Pitaevskii equations.
2007
VARIATIONAL-PRINCIPLES, EINSTEIN CONDENSATE, VORTEX, MECHANICS
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11562/307972
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