2003/03/31 by Pia Mukherjee, Yun Wang · 5 citations
Physics and Astronomy · #CMB cold spot #Cosmic background radiation #Cosmic microwave background #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Galaxies: Formation, Evolution, Phenomena #Hubble's law #Planck #Scalar (mathematics) #Spectral density #Spectral index #Wavelet #astro-ph #hep-ph
paper · pdf · doi:10.1086/379161
published as Astrophys.J.599:1-6,2003 · ApJ accepted. Color figures available upon request from [email protected]
arxiv created 2003/08/19 · openalex publication_date 2003/12/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Reconstructing the shape of the primordial power spectrum in a model-independent way from cosmological data is a useful consistency check on what is usually assumed regarding early universe physics. It is also our primary window to unknown physics during the inflationary era. Using a power-law form for the primordial power spectrum P in ( k ) and constraining the scalar spectral index and its running, in 2003 Peiris and coworkers found that the first-year Wilkinson Microwave Anistropy Probe ( WMAP ) data seem to indicate a preferred scale in P in ( k ). We use two complementary methods, the wavelet band power method of Mukherjee & Wang and the top-hat binning method of Wang, Spergel, & Strauss, to reconstruct P in ( k ) as a free function from cosmic microwave background (CMB) data alone ( WMAP , CBI, and ACBAR), or from CMB data together with large-scale structure data (2dFGRS and PCSz). The shape of the reconstructed P in ( k ) is consistent with scale invariance, although it allows some indication of a preferred scale at k ~ 0.01 Mpc -1 . While consistent with the possible evidence for a running of the scalar spectral index found by the WMAP team, our results highlight the need of more stringent and independent constraints on cosmological parameters (the Hubble constant in particular) in order to more definitively constrain deviations of P in ( k ) from scale invariance without making assumptions about the inflationary model.