Constraints on the Topology of the Universe: Extension to General
  Geometries
  We present an update to the search for a non-trivial topology of the universe
by searching for matching circle pairs in the cosmic microwave background using
the WMAP 7 year data release. We extend the exisiting bounds to encompass a
wider range of possible topologies by searching for matching circle pairs with
opening angles 10 degree < \alpha < 90 degree and separation angles 11 degree <
\theta < 180 degree. The extended search reveal two small anomalous regions in
the CMB sky. Numerous pairs of well-matched circles are found where both
circles pass through one or the other of those regions. As this is not the
signature of any known manifold, but is a likely consequence of contamination
in those sky regions, we repeat the search excluding circle pairs where both
pass through either of the two regions. We then find no statistically
significant pairs of matched circles, and so no hints of a non-trivial
topology. The absence of matched circles increases the lower limit on the
length of the shortest closed null geodesic that self-intersects at our
location in the universe (equivalently the injectivity radius at our location)
to 98.5% of the diameter of the last scattering surface or approximately 26
Gpc. It extends the limit to any manifolds in which the intersecting arcs of
said geodesic form an angle greater than 10^o.
