Correlated Adiabatic and Isocurvature Cosmic Microwave Background Fluctuations in the Wake of the Results from the Wilkinson Microwave Anisotropy Probe

2003/04/30 by Jussi Valiviita, J. Väliviita, Vesa Muhonen · 7 citations
Physics and Astronomy · #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #Relativity and Gravitational Theory #astro-ph #hep-ph

paper · pdf · doi:10.1103/physrevlett.91.131302

published as Phys.Rev.Lett. 91 (2003) 131302 · 5 pages, 7 figures. V2: Added 2 figures and revised a bit the results section. This is a slightly longer version than the published one in PRL

openalex publication_date 2003/09/24 · arxiv created 2003/10/01 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30

Abstract

In general correlated models, in addition to the usual adiabatic component with a spectral index n_ad1 there is another adiabatic component with a spectral index n_ad2 generated by entropy perturbation during inflation. We extend the analysis of a correlated mixture of adiabatic and isocurvature cosmic microwave background fluctuations of the Wilkinson Microwave Anisotropy Probe (WMAP) group, who set the two adiabatic spectral indices equal. Allowing n_ad1 and n_ad2 to vary independently we find that the WMAP data favor models where the two adiabatic components have opposite spectral tilts. Using the WMAP data only, the 2\ensuremathσ upper bound for the isocurvature fraction f_iso of the initial power spectrum at k₀=0.05 Mpc^\ensuremath-1 increases somewhat, e.g., from 0.76 of n_ad2=n_ad1 models to 0.84 with a prior n_iso<1.84 for the isocurvature spectral index.

Cited by

• Inflation dynamics and reheating
• Constraints on isocurvature models from the WMAP first-year data
• Correlated primordial perturbations in light of CMB and large scale structure data
• Density perturbations from both the inflaton and the curvaton
• Cosmological perturbations from varying masses and couplings
• Estimating relic magnetic fields from CMB temperature correlations
• Parameter dependence of magnetized CMB observables

Related

• Correlated adiabatic and isocurvature CMB fluctuations in the light of the WMAP data
• Models of inflation and the spectral index of the adiabatic density perturbation
• Correlated isocurvature perturbations from mixed inflaton-curvaton decay
• Correlated mixtures of adiabatic and isocurvature cosmological perturbations
• Adiabatic and entropy perturbations in cosmology