Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Relaxation of Bose-Einstein Condensates of Magnons in Magneto-Textural
  Traps in Superfluid $^3$He-B   In superfluid $^3$He-B externally pumped quantized spin-wave excitations or
magnons spontaneously form a Bose-Einstein condensate in a 3-dimensional trap
created with the order-parameter texture and a shallow minimum in the
polarizing field. The condensation is manifested by coherent precession of the
magnetization with a common frequency in a large volume. The trap shape is
controlled by the profile of the applied magnetic field and by the condensate
itself via the spin-orbit interaction. The trapping potential can be
experimentally determined with the spectroscopy of the magnon levels in the
trap. We have measured the decay of the ground state condensates after
switching off the pumping in the temperature range $(0.14\div
0.2)T_{\mathrm{c}}$. Two contributions to the relaxation are identified: (1)
spin-diffusion with the diffusion coefficient proportional to the density of
thermal quasiparticles and (2) the approximately temperature-independent
radiation damping caused by the losses in the NMR pick-up circuit. The measured
dependence of the relaxation on the shape of the trapping potential is in a
good agreement with our calculations based on the magnetic field profile and
the magnon-modified texture. Our values for the spin diffusion coefficient at
low temperatures agree with the theoretical prediction and earlier measurements
at temperatures above $0.5T_{\mathrm{c}}$.

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The categories of this paper are: nlin
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The categories of this paper are: eess
32
The categories of this paper are: atom-ph
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The categories of this paper are: acc-phys
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
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The categories of this paper are: solv-int
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The categories of this paper are: nucl-ex
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
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The categories of this paper are: ao-sci
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The categories of this paper are: patt-sol
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The categories of this paper are: quant-ph
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The categories of this paper are: q-alg
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The categories of this paper are: q-fin
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The categories of this paper are: chao-dyn