118869380
Type-I superconductivity and neutron star precession
Type-I proton superconducting cores of neutron stars break up in a magnetic field into alternating domains of superconducting and normal fluids. We examine two channels of superfluid-normal fluid friction where (i) rotational vortices are decoupled from the nonsuperconducting domains and the interaction is due to the strong force between protons and neutrons; (ii) the nonsuperconducting domains are dynamically coupled to the vortices and the vortex motion generates transverse electric fields within them, causing electronic current flow and Ohmic dissipation. The obtained dissipation coefficients are consistent with the Eulerian precession of neutron stars.
16685281
Neutron-Phonon Interaction in Neutron Star Crusts
The phonon spectrum of Coulomb lattice in neutron star crusts above the neutron drip density is affected by the interaction with the ambient neutron Fermi-liquid. For the values of the neutron-phonon coupling constant in the range $0.1 \le \lambda \le 1$ an appreciable renormalization of the phonon spectrum occurs which can lead to a lattice instability manifested in an exponential growth of the density fluctuations. The BCS phonon exchange mechanism of superconductivity leads to neutron pairing with a gap in the neutron excitation spectrum comparable to that due to the direct nuclear interaction.
123150107
Low-temperature transport coefficients of nuclear matter with in-medium modifications
Abstract Transport coefficients of dense symmetrical nuclear matter in the low-temperature regime are calculated taking into account the modifications of the quasi-particle scattering amplitudes in the nuclear environment. The two-body scattering T -matrix, the in-medium nucleon-nucleon cross section, and the critical temperature for the superfluid phase transition for the different partial wave channels are evaluated using a separable form of the nucleon-nucleon interaction. As a precursor effect of the onset of superfluid phase, the transport coefficients show non-trivial rediction with the decreasing temperature. The in-medium transport coefficients are found to be considerably modified compared with the results obtained with either the free scattering cross section or the isotropic residual value σ ∼ 40 mb.
7071448
Neutrino-pair emission in a strong magnetic field
We study the neutrino emissivity of strongly magne- tized neutron stars due to the charged and neutral current cou- plings of neutrinos to baryons in strong magnetic fields. The leading order neutral current process is the one-body neutrino- pair bremsstrahlung, which does not have an analogue in the zero field limit. The leading order charged current reaction is the known generalization of the direct Urca processes to strong magnetic fields. While for superstrong magnetic fields in excess of 10 18 G the direct Urca process dominates the one-body bremsstrahlung, we find that for fields on the order 10 16 10 17 G and temperatures a few times10 9 K the one-body bremsstrahlung is the dominant process. Numerical computa- tion of the resulting emissivity, based on a simple parametriza- tion of the equation of state of the npe-matter in a strong mag- netic field, shows that the emissivity of this reaction is of the same order of magnitude as that of the modified Urca process in the zero field limit.
121705206
Reply to “Comment on ‘Interaction induced deformation of the momentum distribution of spin polarized nuclear matter’ ”
A comparison is made between a Brueckner-Hartree-Fock study of spin polarized nuclear matter allowing for deformation of the Fermi spheres and studies of such systems in terms of the Landau parametrization of the effective interaction.
118545262
Phase diagram of chiral quark matter: Color and electrically neutral Fulde-Ferrell phase
The phase diagram of charge and color neutral two-flavor color superconducting quark matter is studied including the homogeneous two-flavor superconductor (2SC) and the inhomogeneous Fulde-Ferrell (FF) phases within the Nambu-Jona-Lasinio model. The low-temperature domain T{<=}5 MeV of the phase diagram contains the FF phase, which borders at high temperatures to the 2SC phase. The critical temperature of phase transition from the 2SC to the unpaired state is in the range 20-30 MeV. We derive the equation of state of matter and its composition and show that matter in mature compact stars should be in the inhomogeneous FF-like superconducting state. We briefly discuss the astrophysical implications of such a phase in compact stars.
125621539
Many Particle Regge Poles in Supersymmetric Theory