Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Thermal conductivity of ions in a neutron star envelope   We analyze the thermal conductivity of ions (equivalent to the conductivity
of phonons in crystalline matter) in a neutron star envelope.
  We calculate the ion/phonon thermal conductivity in a crystal of atomic
nuclei using variational formalism and performing momentum-space integration by
Monte Carlo method. We take into account phonon-phonon and phonon-electron
scattering mechanisms and show that phonon-electron scattering dominates at not
too low densities. We extract the ion thermal conductivity in ion liquid or gas
from literature.
  Numerical values of the ion/phonon conductivity are approximated by
analytical expressions, valid for T>10^5 K and 10^5 g cm^-3 < \rho < 10^14 g
cm^-3. Typical magnetic fields B~10^12 G in neutron star envelopes do not
affect this conductivity although they strongly reduce the electron thermal
conductivity across the magnetic field. The ion thermal conductivity remains
much smaller than the electron conductivity along the magnetic field. However,
in the outer neutron star envelope it can be larger than the electron
conductivity across the field, that is important for heat transport across
magnetic field lines in cooling neutron stars. The ion conductivity can greatly
reduce the anisotropy of heat conduction in outer envelopes of magnetized
neutron stars.

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The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
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The categories of this paper are: gr-qc
9
The categories of this paper are: nlin
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The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
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The categories of this paper are: econ
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an