General quadrupolar statistical anisotropy: Planck limits

Abstract

Several early Universe scenarios predict a direction-dependent spectrum of primordial curvature perturbations. This translates into the violation of the statistical isotropy of cosmic microwave background radiation. Previous searches for statistical anisotropy mainly focussed on a quadrupolar direction-dependence characterised by a single multipole vector and an overall amplitude $g_{\ast }$. Generically, however, the quadrupole has a more complicated geometry described by two multipole vectors and $g_{\ast }$. This is the subject of the present work. In particular, we limit the amplitude $g_{\ast }$ for different shapes of the quadrupole by making use of Planck 2015 maps. We also constrain certain inflationary scenarios which predict this kind of more general quadrupolar statistical anisotropy.

22 pages, 5 figures; version accepted in JCAP

References in corpus (16)

• Inflationary Universe with Anisotropic Hair
• Detection of Gravitational Lensing in the Cosmic Microwave Background
• Galilean Genesis: an alternative to inflation
• Hemispherical power asymmetry in the three-year Wilkinson Microwave Anisotropy Probe sky maps
• The Nature of Primordial Fluctuations from Anisotropic Inflation
• Cosmic Microwave Background Statistics for a Direction-Dependent Primordial Power Spectrum
• Scalar-Scalar, Scalar-Tensor, and Tensor-Tensor Correlators from Anisotropic Inflation
• Inflationary perturbations in anisotropic backgrounds and their imprint on the CMB
• Anisotropic Power-law Inflation
• Asymmetric Beams and CMB Statistical Anisotropy
• Harrison--Zeldovich spectrum from conformal invariance
• Particle Production of Vector Fields: Scale Invariance is Attractive
• Consistency Relations for the Conformal Mechanism
• Cosmological density perturbations from conformal scalar field: infrared properties and statistical anisotropy
• Scalar perturbations in conformal rolling scenario with intermediate stage
• Revisiting constraints on (pseudo)conformal Universe with Planck data