Saturday, March 25, 2006

3 hours of talks; still odd features in signal

Two 1.5 hour talks by Spergel today. Learned that just
about all the "significant" differences we see in the new
papers come from choices in analysis. For example, they
quoted the mean in the first year paper but they quote
maximum likelihoods in this paper. Many of the
distributions were heavily scewed so it makes a big
difference. In fact, the ML value for the optical depth
in the first year results was 0.1 and it is in the new results
as well. But the mean changed a lot, from 0.17 to 0.1.
It's not clear why the made the change.

I tried to isolate the odd features in the signal, which
shows up in the LRGs and the high Ngal clusters. I split the
LRGs by redshift but the signal remains. I also tried a buffer
that the sources had to be zlens + zbuffer (0.1 and 0.2) but that
made absolutely no difference at all. I also ran with the other
catalog instead of the princeton but this made no difference
either (it never has). The catalog has no objects where were
deblended, but this could still be the problem and we just don't
have a simple indicator.

The feature is not physical, so I must figure out a way to
isolate it. I'm out of ideas at the moment.


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