Ellipsoidal Universe Can Solve The CMB Quadrupole Problem

Abstract

The recent three-year WMAP data have confirmed the anomaly concerning the low quadrupole amplitude compared to the best-fit ΛCDM prediction. We show that, allowing the large-scale spatial geometry of our universe to be plane-symmetric with eccentricity at decoupling or order 10^{-2}, the quadrupole amplitude can be drastically reduced without affecting higher multipoles of the angular power spectrum of the temperature anisotropy.

4 pages, 2 figures, minor changes, reference added, to appear in Phys. Rev. Lett