The Hantzsche-Wendt Manifold in Cosmic Topology
  The Hantzsche-Wendt space is one of the 17 multiply connected spaces of the
three-dimensional Euclidean space E^3. It is a compact and orientable manifold
which can serve as a model for a spatial finite universe. Since it possesses
much fewer matched back-to-back circle pairs on the cosmic microwave background
(CMB) sky than the other compact flat spaces, it can escape the detection by a
search for matched circle pairs. The suppression of temperature correlations
C(theta) on large angular scales on the CMB sky is studied. It is shown that
the large-scale correlations are of the same order as for the 3-torus topology
but express a much larger variability. The Hantzsche-Wendt manifold provides a
topological possibility with reduced large-angle correlations that can hide
from searches for matched back-to-back circle pairs.
