Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Polarization of the CMB photons crossing the galaxy clusters   In this paper, I investigate a local effect of polarization of the Cosmic
Microwave Background (CMB) in clusters of galaxies, due to the Thomson
scattering of the anisotropic radiation. A local anisotropy of the CMB is
produced by some gravitational and scattering effects, as, for instance, the
Sunyaev Zel'dovich effect, the Doppler shift due to the cluster motion and the
gravitational lensing. The resulting anisotropy $\Delta I / I$ depends on the
physical properties of the clusters, in particular on their emissivity in the X
band, their size, their gravitational potential and on the peculiar conditions
characterizing the cluster gas. By solving the Boltzmann radiative transfer
equation in presence of such anisotropies I calculate the average polarization
at the centre of some clusters, namely A2218, A576 and A2163, whose properties
are quite well known. I prove the gravitational effects due to the contraction
or to the expansion of the cluster have some importance and dominate the SZ
effect, particularly for high density stuctures.

22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
19
The categories of this paper are: eess
25
The categories of this paper are: patt-sol
14
The categories of this paper are: math-ph
0
The categories of this paper are: hep-ph
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
1
The categories of this paper are: cs