Year: 1998
Type: article
Abstract: It has been argued that the power spectrum of the anisotropies in the cosmic microwave background may be effectively degenerate, namely, that the observable spectrum does not determine a unique set of cosmological parameters. We describe the physical origin of this degeneracy and show that at small angular scales it is broken by gravitational lensing: effectively degenerate spectra become distinguishable at l ~3000 because lensing causes their damping tails to fall at different rates with increasing l . This effect also helps in distinguishing nearly degenerate power spectra such as those of mixed dark matter models. Forthcoming interferometer experiments should provide the means of measuring otherwise degenerate parameters at the 5%-25% level.
Source: The Astrophysical Journal
DOI: 10.1086/311080
Authors: R. Benton Metcalf, Joseph Silk
Institution: University of California, Berkeley
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W1967402328