Comment on “Transverse Force on a Quantized Vortex in a Superfluid”

Fermion zero-mode influence on neutron-star magnetic field evolution

“…This lags behind v L in general, and in the limits τ c or τ loc →∞ tends, as expected, to v L or v T . Thus, spectral flow (Volovik 1996) depends on the velocity difference In Andreev reflection, a particle (hole) is retroreflected as a hole (particle), so maintaining the orientation of the chord. It has angular momentum , where is its coordinate in the vortex rest frame.…”

“…The Magnus force is expressed in terms of the proton electromagnetic current density J s p obtained from the entrainment coefficients (Andreev & Bashkin 1975; Alpar, Langer & Sauls 1984; Jones 1991), v L and the superfluid bulk velocities, A similar expression gives F l , the electromagnetic interaction with electrons and muons, in terms of the lepton current density J l . The spectral flow force has components parallel with and perpendicular to v L − v T , (Volovik 1996; Kopnin 2002), with where β −1 = k B T . The total proton density is ρ p =ρ s p +ρ n p , but at the temperatures considered here, the normal component ρ n p is negligibly small compared with the superfluid ρ s p .…”

“…A new development in condensed‐matter physics, the phenomenon of spectral flow described by Volovik (1996; see also the review of Kopnin 2002), has greatly clarified and extended our understanding of the forces acting on moving vortices and has been confirmed by measurements on the 3 He‐B phase (Bevan et al 1997). The present paper applies these ideas to show that forces generated by spectral flow limit the velocities of proton vortices in the outer core of hot young neutron stars to an extent that is consistent with a large fraction of the active flux not linking the core.…”

Comment on “Magnus and Iordanskii Forces in Superfluids”

“…We wish to point out that this conclusion conflicts with the experimental facts for vortices in superfluid 3 He and 4 He, irrespective of any theory offered to explain those facts, as in an earlier Comment [2].…”

Longitudinal force on a moving potential

“…2 However, this result is controversial. [4][5][6] The discrepancy may come from using different calculation schemes, or it may come from inadequate handling of boundary conditions in some or all of the calculations. 3 TAN's derivation uses the time-dependent perturbation theory in contrast to the usual approach using scattering theory and kinetic equations.…”