1999/02/01 by Alexander Vilenkin · 2 citations
Mathematics · Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Applied mathematics #Computer science #Cosmology and Gravitation Theories #Factor (programming language) #Geometry #Inflation (cosmology) #Invariant (physics) #Mathematical economics #Mathematical physics #Mathematics #Physics #Scalar (mathematics) #Set (abstract data type) #Solar and Space Plasma Dynamics #Statistical physics #Theoretical physics #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1103/physrevd.59.123506
published as Phys. Rev. D 59, 123506 (1999) · 7 pages, revtex
arxiv created 1999/02/01 · openalex publication_date 1999/05/05 · arxiv updated 2016/08/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The stochastic approach to inflation suffers from ambiguities due to the arbitrary choice of the time variable and due to the choice of the factor ordering in the corresponding Fokker-Planck equation. Here it is shown that both ambiguities can be removed if we require that the factor ordering should be set in such a way that physical results are invariant with respect to time reparametrizations. This requirement uniquely selects the so-called Ito factor ordering. Additional ambiguities associated with non-trivial kinetic terms of the scalar fields are also discussed, as well as ways of constraining these ambiguities.