Non-detection of a statistically anisotropic power spectrum in large-scale structure

作者：Pullen Anthony R^*; Hirata Christopher M

来源：Journal of Cosmology and Astroparticle Physics, 2010, (5): 027.

DOI：10.1088/1475-7516/2010/05/027

• power spectrum
• galaxy surveys

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(k) is an isotropic power spectrum (P) over bar (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) over bar (k) = (P) over bar (k){1 + g(*)[((k) over cap . (n) over cap)(2) -1/3]} where (n) over cap is the axis of the anisotropy. When we force the symmetry axis (n) over cap to be in the direction (l, b) = (94 degrees, 26 degrees) identified in the recent Groeneboom et al. analysis of the cosmic microwave background, we find g(*) = 0.006+/-0.036 (1 sigma). With uniform priors on (n) over cap 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.

• 出版日期2010-5