2002/04/23 by Ghazal Geshnizjani, Robert Brandenberger · 187 citations
Mathematics · Physics and Astronomy · #Astrophysics #Back-reaction #Black Holes and Theoretical Physics #Classical mechanics #Cosmology #Cosmology and Gravitation Theories #Dark energy #Field (mathematics) #Galaxies: Formation, Evolution, Phenomena #Geometry #Inflation (cosmology) #Mathematical physics #Mathematics #Metric expansion of space #Physics #Scalar (mathematics) #Scalar field #Theoretical physics #Universe #astro-ph #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1103/physrevd.66.123507
published in Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 66(12) (American Physical Society) · 7 pages, No figures
arxiv created 2002/04/23 · openalex publication_date 2002/12/18 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We calculate the back reaction of cosmological perturbations on a general relativistic variable which measures the local expansion rate of the Universe. Specifically, we consider a cosmological model in which matter is described by a single field. We analyze back reaction both in a matter-dominated Universe and in a phase of scalar field-driven chaotic inflation. In both cases, we find that the leading infrared terms contributing to the back reaction vanish when the local expansion rate is measured at a fixed value of the matter field which is used as a clock, whereas they do not appear to vanish if the expansion rate is evaluated at a fixed value of the background time. We discuss possible implications for more realistic models with a more complicated matter sector.