Work

Large-scale cosmic microwave background anisotropies and dark energy

Year: 2003

Type: article

Abstract: In this paper we investigate the effects of perturbations in a dark energy component with a constant equation of state on large-scale cosmic microwave background (CMB) anisotropies. The inclusion of perturbations increases the large-scale power. We investigate more speculative dark energy models with w < −1 and find the opposite behaviour. Overall the inclusion of perturbations in the dark energy component increases the degeneracies. We generalize the parametrization of the dark energy fluctuations to allow for an arbitrary constant sound speed, and we show how constraints from CMB experiments change if this is included. Combining CMB with large-scale structure, Hubble parameter and supernovae observations we obtain w=−1.02 ± 0.16 (1σ) as a constraint on the equation of state, which is almost independent of the sound speed chosen. With the presented analysis we find no significant constraint on the constant speed of sound of the dark energy component.

Source: Monthly Notices of the Royal Astronomical Society

DOI: 10.1111/j.1365-2966.2003.07144.x

Authors: J. Weller, A. M. Lewis

Institutions: University of Cambridge, Canadian Institute for Theoretical Astrophysics

Language: English

Topic: Cosmology and Gravitation Theories

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: bronze

Funder: Leverhulme Trust

OpenAlex ID: W1987225181