TY - JOUR
T1 - Coarse-graining approach to quantum cosmology
AU - Calzetta, Esteban
AU - Castagnino, Mario
AU - Scoccimarro, Romn
PY - 1992
Y1 - 1992
N2 - We consider a Friedmann-Robertson-Walker model with both classical radiation and a massive (conformally coupled) quantum scalar field in the framework of quantum cosmology. We define a density matrix and introduce a notion of "relevance" which splits this density matrix into a "relevant" and an "irrelevant" part. A "generalized coarse-graining method" is used to obtain the evolution (in Robertson-Walker a "time") of the relevant density matrix, taking into account the back reaction of the irrelevant variables. We discuss the physical basis for the choice of a concept of relevance, and the features of cosmic evolution brought forward by the effective dynamics. In the limit of "small universes," the relevant subdynamics is dissipative.
AB - We consider a Friedmann-Robertson-Walker model with both classical radiation and a massive (conformally coupled) quantum scalar field in the framework of quantum cosmology. We define a density matrix and introduce a notion of "relevance" which splits this density matrix into a "relevant" and an "irrelevant" part. A "generalized coarse-graining method" is used to obtain the evolution (in Robertson-Walker a "time") of the relevant density matrix, taking into account the back reaction of the irrelevant variables. We discuss the physical basis for the choice of a concept of relevance, and the features of cosmic evolution brought forward by the effective dynamics. In the limit of "small universes," the relevant subdynamics is dissipative.
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U2 - 10.1103/PhysRevD.45.2806
DO - 10.1103/PhysRevD.45.2806
M3 - Article
AN - SCOPUS:0011512196
SN - 1550-7998
VL - 45
SP - 2806
EP - 2813
JO - Physical review D: Particles and fields
JF - Physical review D: Particles and fields
IS - 8
ER -