Speaker
Description
We compute the thermal conductivity and thermoelectric power
(thermopower) of the inner crust of compact stars across a broad
temperature–density domain relevant for proto–neutron stars, binary
neutron-star mergers, and accreting neutron stars. The analysis
covers the transition from a semi-degenerate to a highly degenerate
electron gas and assumes temperatures above the melting threshold of
the nuclear lattice, such that nuclei form a liquid. The transport
coefficients are obtained by solving the Boltzmann kinetic equation
in the relaxation-time approximation, fully incorporating the
anisotropies generated by non-quantizing magnetic fields. Electron
scattering rates include (i) dynamical screening of the electron–ion
interaction in the hard-thermal-loop approximation of QED, (ii)
ion–ion correlations within a one component plasma, and (iii) finite
nuclear-size effects. As an additional refinement, we evaluate
electron–neutron scattering induced by the coupling of electrons to
the anomalous magnetic moment of free neutrons; this contribution is
found to be subdominant throughout the parameter range explored. To
assess the sensitivity of transport coefficients to the underlying
microphysics, we perform calculations for several inner-crust
compositions obtained from different nuclear interactions and
many-body methods. Across most of the crust, variations in
relaxation times and in the components of the anisotropic
thermal-conductivity and thermopower tensors reach up to factors
$3$ to $4$ and $1.5$ to $2$, respectively, with the exception of the
region where pasta phases are expected. These results provide
updated, composition-dependent microphysical inputs for dissipative
magneto-hydrodynamic simulations of warm neutron stars and
post-merger remnants, where anisotropic heat and charge transport
are of critical importance.