1996/02/28 by J. L. Sanz, Jose L. Sanz, E. Martínez-González +10
Physics and Astronomy · #Astrophysics (astro-ph) #Cosmology and Gravitation Theories #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #Radio Astronomy Observations and Technology #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9602148
plain tex, 8 pages, 4 figures
arxiv created 1996/02/28 · openalex publication_date 1996/02/28 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A second--order perturbation theory approach is developed to calculate temperature anisotropies in the cosmic microwave background. Results are given for open universes and fluctuations corresponding to CDM models with either Harrison-Zeldovich (HZ) or Lyth-Stewart-Ratra-Peebles (LSRP) primordial energy--density fluctuation power spectrum. Our perturbation theory approach provides a distinctive multipole contribution as compared to the primary one, the amplitude of the effect being very dependent on normalization. For low--Ω models, the contribution of the secondary multipoles to the radiation power spectrum is negligible both for standard recombination and reionized scenarios, with the 2--year COBE--DMR normalization. For a flat universe this contribution is ≈ 0.1-10% depending on the reionization history of the universe and on the normalization of the power spectrum.