A viable explanation of the CMB dipolar statistical anisotropy

Sugumi Kanno, Misao Sasaki, Takahiro Tanaka

Research output: Contribution to journalArticlepeer-review

35 Citations (Scopus)

Abstract

The presence of a dipolar statistical anisotropy in the spectrumof cosmicmicrowave background (CMB) fluctuations was reported by the Wilkinson Microwave Anisotropy Probe (WMAP), and has recently been confirmed in the Planck 2013 analysis of the temperature anisotropies. At the same time, the Planck 2013 results report a stringent bound on the amplitude of the local-type non-Gaussianity.We show that the non-linear effect of the dipolar anisotropy generates not only a quadrupole moment in the CMB but also a local-type non-Gaussianity. Consequently, it is not easy to build models having a large dipolar modulation and at the same time a sufficiently small quadrupole and level of local bispectral anisotropy to agree with the present data. In particular, most models proposed so far are almost excluded, or are at best marginally consistent with observational data. We present a simple alternative scenario that may explain the dipolar statistical anisotropy while satisfying the observational bounds on both the quadrupole moment and local-type non-Gaussianity.

Original languageEnglish
Article number111E01
JournalProgress of Theoretical and Experimental Physics
Volume2013
Issue number11
DOIs
Publication statusPublished - Nov 1 2013
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

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