2001/11/01 by Steven Gratton, Antony Lewis, Neil Turok · 41 citations
Physics and Astronomy · #Astrophysics #Cosmic microwave background #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #Inflation (cosmology) #Instanton #Mathematical physics #Physics #Quantum mechanics #Solar and Space Plasma Dynamics #Theoretical physics #Universe #astro-ph #gr-qc #hep-th
paper · pdf · doi:10.1103/physrevd.65.043513
published in Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 65(4) (American Physical Society) · 12 pages, 6 figures
arxiv created 2001/11/01 · openalex publication_date 2002/01/28 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Current observational data are consistent with the universe being slightly closed. We investigate families of singular and nonsingular closed instantons that could describe the beginning of a closed inflationary universe. We calculate the scalar and tensor perturbations that would be generated from singular instantons and compute the corresponding CMB power spectrum in a universe with cosmological parameters like our own. We investigate spatially homogeneous modes of the instantons, finding unstable modes which render the instantons subdominant contributions in the path integral. We show that a suitable condition may be imposed on singular closed instantons, constraining their instabilities. With this constraint these instantons can provide a suitable model of the early universe, and predict CMB power spectra in close agreement with the predictions of slow-roll inflation.