Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Polarization of the CMB Anisotropy   I review why we expect the CMB anisotropy to be polarized, what we can learn
from studying polarization and the level of the experimental challenge it
presents. A discussion of current and future polarization sensitive experiments
will focus on the expected sensitivity of PLANCK.

29
The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
23
The categories of this paper are: solv-int
3
The categories of this paper are: physics
32
The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
34
The categories of this paper are: chem-ph
28
The categories of this paper are: alg-geom
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci