Year: 1996
Type: article
Abstract: We consider structure formation and cosmic microwave background (CM B) anisotropies in a closed universe, both with and without a cosmological constant. The CMB angular power spectrum and the matter transfer function are presented, along with a discussion of their relative normalization. This represents the first full numerical evolution of density perturbations and anisotropies in a spherical geometry. We extend the likelihood function versus from the COBE 2 year data to > 1. For large the presence of a very steep rise in the spectrum toward low t' allows us to put an upper limit of < 1.5 (95% CL) for primordial spectra with n < 1. This compares favorably with existing limits on . We show that there are a range of closed models that are consistent with observational constraints while being even older than the currently popular flat models with a cosmological constant. Future constraints from degree scale CMB data may soon probe this region of parameter space. A derivation of the perturbed Einstein, fluid, and Boltzmann equations for open and closed geometries is presented in an Appendix.
Source: The Astrophysical Journal
DOI: 10.1086/176904
Authors: Martin White, Douglas Scott
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2121323810