Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Limits on the detectability of the CMB B-mode polarization imposed by
  foregrounds   We investigate which practical constraints are imposed by foregrounds to the
detection of the B-mode polarization generated by gravitational waves in the
case of experiments of the type currently being planned. Because the B-mode
signal is probably dominated by foregrounds at all frequencies, the detection
of the cosmological component depends drastically on our ability for removing
foregrounds. We provide an analytical expression to estimate the level of the
residual polarization for Galactic foregrounds, according to the method
employed for their subtraction. We interpret this result in terms of the lower
limit of the tensor-to-scalar ratio r that allows to disentangle the
cosmological B-mode polarization from the foregrounds contribution. Polarized
emission from extragalactic radio sources and gravitational lensing is also
taken into account. As a first approach, we consider the ideal limit of an
instrumental noise--free experiment: for a full--sky coverage and a degree
resolution, we obtain a limit of r~10^(-4). This value can be improved by
high--resolution experiments and, in principle, no clear fundamental limit on
the detectability of gravitational waves polarization is found. Our analysis is
also applied to planned or hypothetical future polarization experiments, taking
into account expected noise levels.

8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
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The categories of this paper are: chao-dyn
25
The categories of this paper are: patt-sol
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The categories of this paper are: eess