Robust Dark Energy Constraints from Supernovae, Galaxy Clustering, and 3 yrWilkinson Microwave Anisotropy ProbeObservations
Year: 2006
Type: article
Abstract: Type Ia supernova (SN Ia), galaxy clustering, and cosmic microwave background (CMB) anisotropy data provide complementary constraints on the nature of the dark energy in the universe. We find that the 3 yr Wilkinson Microwave Anisotropy Probe ( WMAP ) observations give a CMB shift parameter of R ≡ 1/2 dz '/ H ( z ') = 1.70 ± 0.03. Using this new measured value of the CMB shift parameter, together with the baryon acoustic oscillation (BAO) measurement from the Sloan Digital Sky Survey (SDSS), and SN Ia data from the HST /GOODS program and the first-year Supernova Legacy Survey, we derive model-independent constraints on the dark energy density ρ X ( z ) and the cosmic expansion rate H ( z ). We also derive constraints on the dark energy equation of state w X ( z ) = w 0 + w ' z (with cutoff at z = 2) and w X ( a ) = w 0 + (1 - a ) w a . We find that current data provide slightly tighter constraints on ρ X ( z ) and H ( z ) as free functions in redshift and roughly a factor of 2 improvement in constraining w X ( z ). A cosmological constant remains consistent with the data; however, uncertainties remain large for model-independent constraints of dark energy. A significant increase in the number of observed SNe Ia between redshifts of 1 and 2, complemented by improved BAO and weak-lensing cosmography measurements (as expected from the JEDI mission concept for the Joint Dark Energy Mission ), will be required to dramatically tighten model-independent dark energy constraints.
Source: The Astrophysical Journal
DOI: 10.1086/507091
Authors: Yun Wang, Pia Mukherjee
Institutions: University of Oklahoma, University of Sussex
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Funder: National Science Foundation
OpenAlex ID: W2087739892