English

Subdynamics of relevant observables: a field theoretical approach

Quantum Physics 2009-11-07 v1

Abstract

An approach to the description of subdynamics inside non-relativistic quantum field theory is presented, in which the notions of relevant observable, time scale and complete positivity of the time evolution are stressed. A scattering theory derivation of the subdynamics of a microsystem interacting through collisions with a macrosystem is given, leading to a master-equation expressed in terms of the operator-valued dynamic structure factor, a two-point correlation function which compactly takes the statistical mechanics properties of the macrosystem into account. For the case of a free quantum gas the dynamic structure factor can be exactly calculated and in the long wavelength limit a Fokker-Planck equation for the description of quantum dissipation and in particular quantum Brownian motion is obtained, where peculiar corrections due to quantum statistics can be put into evidence.

Keywords

Cite

@article{arxiv.quant-ph/0204091,
  title  = {Subdynamics of relevant observables: a field theoretical approach},
  author = {Ludovico Lanz and Bassano Vacchini},
  journal= {arXiv preprint arXiv:quant-ph/0204091},
  year   = {2009}
}

Comments

28 pages, latex, no figures

R2 v1 2026-07-22T19:34:35.634Z