Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Discrete Breathers in Anisotropic Ferromagnetic Spin Chains   We prove the existence of discrete breathers (time-periodic, spatially
localized solutions) in weakly coupled ferromagnetic spin chains with easy-axis
anisotropy. Using numerical methods we then investigate the continuation of
discrete breather solutions as the intersite coupling is increased. We find a
band of frequencies for which the 1-site breather continues all the way to the
soliton solution in the continuum. There is a second band, which abuts the
first, in which the 1-site breather does not continue to the soliton solution,
but a certain multi-site breather does. This banded structure continues, so
that in each band there is a particular multi-site breather which continues to
the soliton solution. A detailed analysis is presented, including an exposition
of how the bifurcation pattern changes as a band is crossed. The linear
stability of breathers is analyzed. It is proved that 1-site breathers are
stable at small coupling, provided a non-resonance condition holds, and an
extensive numerical stability analysis of 1-site and multisite breathers is
performed. The results show alternating bands of stability and instability as
the coupling increases.

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The categories of this paper are: math-ph
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The categories of this paper are: adap-org
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The categories of this paper are: supr-con
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The categories of this paper are: comp-gas
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The categories of this paper are: solv-int
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The categories of this paper are: dg-ga
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The categories of this paper are: q-fin
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The categories of this paper are: nucl-th
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-lat
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The categories of this paper are: acc-phys
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The categories of this paper are: funct-an
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The categories of this paper are: plasm-ph
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The categories of this paper are: physics
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The categories of this paper are: econ
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The categories of this paper are: alg-geom