Hi Boud,
I've  just had such a though.
If we assumed some multiply-connected space-time within some model (eg. 
dodecahedral) then my question is whether is leads to nongaussian (NG) 
features in CMB. I think it definitely should.
Such spacetime, gives a modified power spectrum of fluctuations, limited to
fundamental domain size and there should be repercusions of this size
in harmonic modes that are natural multiple of that size. Then given a feature 
at one length scale should automatically give features at other scales - 
hence vialation of gaussianity. This could be investigated by bi- or 
tri-spectrum optimalized for these particular perturbation modes that come 
from the model. Given NG simulations one could estimate the sensityvity of
this approach.
This is also a test of the multiply connected space hypothesis.
Is that right ?
What I would need is to have a full fourier space of perturbations with 
topology encoded in it.
pozdr.
Bartek