WAVE-FUNCTION COLLAPSE AND THE QUANTUM FLUCTUATION-DISSIPATION PROCESS

We study the effect that the state-vector reduction of Ghirardi, Rimin i, and Weber (GRW) [Phys. Rev. D 34, 470 (1986)] has on the quantum fl uctuation-dissipation process. A conventional fluctuation-dissipation process stems from the interaction between a system of interest and a macroscopic number of microscopic variables, thereby suggesting the po ssible occurrence of an enhancement of the GRW wave-function collapse. We carry out an exact treatment of the joint action of conventional q uantum dissipation and GRW wave-function collapse in the special case where the system of interest is a harmonic oscillator. We prove that t he GRW dynamics does not lead to any significant departure from the pr edictions of ordinary quantum mechanics, if the region of astronomical ly large times is disregarded, where the energy of the system diverges as an effect of a slow but steady increase caused by the GRW collapse s.