1997/05/21 by Takahiro Tanaka, Masa-aki Sakagami, M. Sakagami · 2 citations
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Cosmology and Gravitation Theories #Statistical Mechanics and Entropy #gr-qc
paper · pdf · doi:10.1143/ptp.100.547
published as Prog.Theor.Phys. 100 (1998) 547-580 · 23 pages, submitted to Phys. Rev. D15
arxiv created 1997/05/21 · openalex publication_date 1998/09/01 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Taking into account the effect of self-interaction, the dynamics of the quantum fluctuations of the inflaton field with a λϕ4 potential is studied in detail. We find that the self-interaction efficiently drives the initial pure state into a mixed state, which can be understood as a statistical ensemble. Further, the expectation value of the squared field operator is found to be converted into the variance of this statistical ensemble without giving any significant change in the amplitude of fluctuations. These results verify the ansatz of the quantum-to-classical transition that has been assumed in the standard evaluation of the amplitude of the primordial fluctuations of the universe.