Speaker
Prof.
Andrzej Radosz
(Institute of Theoretical Physics, Wroclaw University of Science and Technology, Wroclaw, Poland)
Description
In a large class of cosmological models quantization of a scalar free field leads to the picture of a system of harmonic oscillators coupled via terms corresponding to creation/annihilation of pairs of particles, obeying momentum conservation. In such a case, an evolution of a creation/annihilation operators, meant as a Bogolyubov transformation, may be regarded as a “rotation” in a two-dimensional, (k, -k) sub-space. One can argue, that if the Bogolyubov coefficients are found, then the evolution of an initial vaccum state may be described in a rigorous manner, even if it is a non-unitary evolution.
Evolution of multiparticle states will be discussed.
Author
Prof.
Andrzej Radosz
(Institute of Theoretical Physics, Wroclaw University of Science and Technology, Wroclaw, Poland)