Abstract

WMAP's nearly all-sky map of the CMB and the various all-sky maps
inferred from the WMAP data offer the possibility for learning
about the properties of the universe on the largest scale.
In this talk, I will focus on two questions -- cosmic topology
and statistical isotropy -- and on two techniques
-- circles in the sky and multipole vector analysis -- as methods
of addressing these questions. I will review the results obtained
so far -- that there is no evidence for non-trivial cosmic topology
(and strong evidence against certain topologies);
but that either the universe on large scales is much stranger
than we had imagined or there is a systematic (instrumental or
foreground) contamination of the CMB.