Douglas Applegate wrote: ... is it plausible that an incorrect
model for the telescope pointing would result in a mis-measured
quadrapole?
Bennett et al 2003 arXiv:
astro-ph/0302207 give 3.3mK for the dipole.
[tex] \sin(7') * 3.3mK = 0.002 * 3.3mK = 6.7 \mu K[/tex]
Liu and Li say 10-20 [tex]\mu K[/tex], just slightly higher. Sounds close
enough to me for
plausibility.
The direction of the expected error should vary as the direction of
observation varies, so it seems reasonable to me that it doesn't give
a simple offset detectable by the standard post-processing pipeline.
This gives plausibility of why nobody detected this by post-processing
tests.
Step-by-step tests presumably missed it because taking the middle
point of an interval sounds right. Liu and Li state that in fact,
it's wrong, because it's used as the
start of an interpolation
interval, not as a mid-value. At least, that's how I interpret the
text. A Nature-letter-type paper prevents the authors from including
any serious details.
Douglas Applegate wrote:Putting aside the hard question of
correctness,
Figure 2-left is calculated using
only the directional
information from the time-ordered-data from the spacecraft, with
no CMB data except for the dipole direction (if I understand
correctly). See paragraph 2, page 4:
"only the spacecraft attitude
information is used to compute d' ." I have not checked this
calculation for correctness myself. I have also not checked the
quaternion directional representation and interpolation methods. But
these should presumably be computationally quite fast to calculate -
no reading in of CMB maps is necessary at all. So I would say that
reproducing Fig 2-left is not that hard.
Digging through the data pipeline papers, finding the quaternions and
the interpolation process, are probably also not that hard. It just
would take time for people not familiar enough with the papers.
Doing Fig 1-right-panel is what would presumably take a lot of work
for someone who has not already set up and tested the pipeline for
analysing the TOD. But Fig 2-left should IMHO be enough to establish
that another "conspiracy" has been found - an analysis error in
spacecraft pointing agrees surprisingly well with what has been
widely considered to be a low amplitude, but detected, CMB quadrupole.
Cosmological interpretation: the Polish relativist Leopold
Infeld would presumably have said "I told you so!" if he were still
alive. He seems to be the first person (Infeld 1949) to have predicted
the disappearance of fluctuation statistics on scales larger than the
size of the Universe if the Universe is a compact FLRW model in the
sense of Friedmann, Lemaitre and Robertson. [See e.g. Roukema 2010
1002.3528 and follow the references if you need an introduction
to observational and (very few) theoretical aspects of cosmic
topology. I was only recently alerted to Infeld's prior claim to the
low k (low l) cutoff argument, so I haven't yet referred to it in any
formal publication.]
i think that along with inhomogeneous universe exact (Krasiński,
Célérier et al.) and averaging (Buchert et al.) approaches, the
Concordance Model is becoming more and more of a phenomenological
fit and less and less of a physical model.