Current constraints on Cosmological Parameters from Microwave Background Anisotropies

Abstract

We compare the latest observations of Cosmic Microwave Background (CMB) Anisotropies with the theoretical predictions of the standard scenario of structure formation. Assuming a primordial power spectrum of adiabatic perturbations we found that the total energy density is constrained to be ${\Omega }_{tot}=1.03\pm 0.06$ while the energy density in baryon and Cold Dark Matter (CDM) are ${\Omega }_b{h}^2=0.021\pm 0.003$ and ${\Omega }_{cdm}{h}^2=0.12\pm 0.02$, (all at 68% C.L.) respectively. The primordial spectrum is consistent with scale invariance, ($n_s=0.97\pm 0.04$) and the age of the universe is $t_0=14.6\pm 0.9$ Gyrs. Adding informations from Large Scale Structure and Supernovae, we found a strong evidence for a cosmological constant ${\Omega }_{\Lambda }=0.70_{-0.05}^{+0.07}$ and a value of the Hubble parameter $h=0.69\pm 0.07$. Restricting this combined analysis to flat universes, we put constraints on possible 'extensions' of the standard scenario. A gravity waves contribution to the quadrupole anisotropy is limited to be $r\le 0.42$ (95% c.l.). A constant equation of state for the dark energy component is bound to be $w_Q\le -0.74$ (95% c.l.). We constrain the effective relativistic degrees of freedom $N_{\nu }\le 6.2$ and the neutrino chemical potential $-0.01\le {\xi }_e\le 0.18$ and $|{\xi }_{\mu ,\tau }|\le 2.3$ (massless neutrinos).

The status of cosmological parameters before WMAP. In press on Phys. Rev. D., Rapid Communication, 6 pages, 5 figures

References in corpus (1)

• The Inflationary Gravity Waves in light of recent Cosmic Microwave Background Anisotropies data

Cited by in corpus (16)

• Generalized Chaplygin gas as a unified scenario of dark matter/energy: observational constraints
• A Horizon Ratio Bound for Inflationary Fluctuations
• Modelling galaxy halos using dark matter with pressure
• Bayesian Analysis of the Chaplygin Gas and Cosmological Constant Models using the SNe Ia Data
• Constraints on Scalar-Field Dark Energy from Galaxy Cluster Gas Mass Fraction versus Redshift
• Constraints on Scalar-Field Dark Energy from the Cosmic Lens All-Sky Survey Gravitational Lens Statistics
• Supernova Ia and Galaxy Cluster Gas Mass Fraction Constraints on Dark Energy
• An inflation model with large variations in spectral index
• Constraints on Cardassian Scenario from the Expansion Turnaround Redshift and the Sunyaev-Zeldovich/X-ray Data
• CMB constraints on interacting cosmological models
• The running-mass inflation model and WMAP
• Recombining WMAP: constraints on ionizing and resonance radiation at recombination
• An ISOCAM survey through gravitationally lensing galaxy clusters. II. The properties of infrared galaxies in the A2218 field
• COBE-DMR-Normalized Dark Energy Cosmogony
• Mass Varying Neutrinos, Quintessence, and the Accelerating Expansion of the Universe
• The shape of the CMB power spectrum