2010/03/31 by Anthony R. Pullen, Christopher M. Hirata
Physics and Astronomy · #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #Radio Astronomy Observations and Technology #astro-ph.CO
paper · pdf · doi:10.1088/1475-7516/2010/05/027
published as JCAP05:27,2010 · 23 pages; 10 figures; 3 tables; replaced with version published in JCAP (added discussion of scale-varying quadrupolar anisotropy)
arxiv created 2010/05/21 · openalex publication_date 2010/05/21 · arxiv updated 2010/05/25 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
We search a sample of photometric luminous red galaxies (LRGs) measured by the Sloan Digital Sky Survey (SDSS) for a quadrupolar anisotropy in the primordial power spectrum, in which P ( ) is an isotropic power spectrum ( k ) multiplied by a quadrupolar modulation pattern. We first place limits on the 5 coefficients of a general quadrupole anisotropy. We also consider axisymmetric quadrupoles of the form P ( ) = ( k )1+ g * [( ⋅ ) 2 −(1/3)] where is the axis of the anisotropy. When we force the symmetry axis to be in the direction ( l , b ) = (94°,26°) identified in the recent Groeneboom et al. analysis of the cosmic microwave background, we find g * = 0.006±0.036 (1σ). With uniform priors on and g * we find that −0.41 < g * < +0.38 with 95% probability, with the wide range due mainly to the large uncertainty of asymmetries aligned with the Galactic Plane. In none of these three analyses do we detect evidence for quadrupolar power anisotropy in large scale structure.