Probing the anisotropic expansion history of the universe with cosmic
  microwave background
  We propose a simple technique to detect any anisotropic expansion stage in
the history of the universe starting from the inflationary stage to the surface
of last scattering from the CMBR data. We use the property that any anisotropic
expansion in the universe would deform the shapes of the primordial density
perturbations and this deformation can be detected in a shape analysis of
superhorizon fluctuations in CMBR. Using this analysis we obtain the constraint
on any previous anisotropic expansion of the universe to be less than about
35%.
