Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Estimating the Power Spectrum of the Cosmic Microwave Background   We develop two methods for estimating the power spectrum, C_l, of the cosmic
microwave background (CMB) from data and apply them to the COBE/DMR and
Saskatoon datasets. One method involves a direct evaluation of the likelihood
function, and the other is an estimator that is a minimum-variance weighted
quadratic function of the data. Applied iteratively, the quadratic estimator is
not distinct from likelihood analysis, but is rather a rapid means of finding
the power spectrum that maximizes the likelihood function. Our results bear
this out: direct evaluation and quadratic estimation converge to the same C_ls.
The quadratic estimator can also be used to directly determine cosmological
parameters and their uncertainties. While the two methods both require O(N^3)
operations, the quadratic is much faster, and both are applicable to datasets
with arbitrary chopping patterns and noise correlations. We also discuss
approximations that may reduce it to O(N^2) thus making it practical for
forthcoming megapixel datasets.

13
The categories of this paper are: quant-ph
4
The categories of this paper are: cond-mat
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
21
The categories of this paper are: adap-org
29
The categories of this paper are: funct-an
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
3
The categories of this paper are: physics
17
The categories of this paper are: q-fin
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th