Coarse-graining approach to quantum cosmology

Esteban Calzetta, Mario Castagnino, Romn Scoccimarro

    Research output: Contribution to journalArticlepeer-review


    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.

    Original languageEnglish (US)
    Pages (from-to)2806-2813
    Number of pages8
    JournalPhysical Review D
    Issue number8
    StatePublished - 1992

    ASJC Scopus subject areas

    • Physics and Astronomy (miscellaneous)


    Dive into the research topics of 'Coarse-graining approach to quantum cosmology'. Together they form a unique fingerprint.

    Cite this