Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Galactic dynamo seeds from non-superconducting spin-polarised strings   Earlier Enqvist and Olesen have shown that formation of ferromagnetic planar
walls in vacuum at GUT scales in comoving plasmas may generate a large scale
magnetic field of $B_{now}\simeq{10^{-14}G}$. In this paper we show that
starting from classical Einstein-Cartan-Maxwell strong gravity, a
spin-polarised ferromagnetic cylinder gives rise to a cosmological magnetic
field of the order $B_{now}\simeq{10^{-22}G}$. Vorticity of cylinder is used to
obtain galactic magnetic fields. Magnetic fields up to $B\sim{10^{9}G}$ can be
obtained from the spin density of the cylinder. If matching conditions are used
cosmological magnetic fields of the order of $B\sim{10^{-16}R\frac{Gauss}{cm}}$
where $R$ is the radius of the cosmic strings. For a cosmic string with the
radius of an hydrogen atom the cosmic magnetic field is $B\sim{10^{-32}Gauss}$
which is enough to seed galactic dynamos.

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The categories of this paper are: q-alg
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The categories of this paper are: eess
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The categories of this paper are: comp-gas
18
The categories of this paper are: econ
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The categories of this paper are: adap-org
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The categories of this paper are: bayes-an
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The categories of this paper are: quant-ph
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
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The categories of this paper are: math-ph
8
The categories of this paper are: hep-ex
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The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
31
The categories of this paper are: ao-sci
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The categories of this paper are: q-fin
2
The categories of this paper are: math