10967331
Spin Evolution of Pulsars with Weakly Coupled Superfluid Interiors
We discuss the spin evolution of pulsars in the case where a superfluid component of the star is coupled to the observable crust on long, spin-down timescales. The momentum transfer from the superfluid interior results in an apparent decay of the external torque and, after a dramatic increase, in an asymptotic decrease of the generic value of the braking index, e.g., n = 3, to values n ~ 2.5 if the magnetic field of the star does not decay over its lifetime. In the case where an exponential decay of the magnetic field toward a residual value occurs, the star undergoes a spin-up phase after which it could emerge in the millisecond sector of the P- diagram.
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.
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.
13148979
SUPERCONDUCTIVITY WITH DEFORMED FERMI SURFACES AND COMPACT STARS
I discuss the deformed Fermi surface superconductivity (DFS) and some of its alternatives in the context of nucleonic superfluids and two flavor color superconductors that may exist in the densest regions of compact stellar objects.
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.
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.
125621539
Many Particle Regge Poles in Supersymmetric Theory