Coarse-graining approach to quantum cosmology
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 "releva...
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| Autores principales: | , , |
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| Formato: | JOUR |
| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_05562821_v45_n8_p2806_Calzetta |
| Aporte de: |
| Sumario: | 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. © 1992 The American Physical Society. |
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