Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Can topological defects mimic the BICEP2 B-mode signal?   We show that the B-mode polarization signal detected at low multipoles by
BICEP2 cannot be entirely due to topological defects. This would be
incompatible with the high-multipole B-mode polarization data and also with
existing temperature anisotropy data. Adding cosmic strings to a model with
tensors, we find that B-modes on their own provide a comparable limit on the
defects to that already coming from Planck satellite temperature data. We note
that strings at this limit give a modest improvement to the best-fit of the
B-mode data, at a somewhat lower tensor-to-scalar ratio of $r \simeq 0.15$.

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The categories of this paper are: acc-phys
8
The categories of this paper are: hep-ex
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: supr-con
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The categories of this paper are: dg-ga
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The categories of this paper are: solv-int
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The categories of this paper are: chao-dyn
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The categories of this paper are: math-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: econ
5
The categories of this paper are: gr-qc
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The categories of this paper are: adap-org
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The categories of this paper are: nucl-th