arXiv subjects
Publications and source records attributed to G. V. Vlasov.
We develope a theory of sound in a relativistic superfluid with quantum vortices. The vortices are presented by vortex fluid. For a particular separable model we find new modes of which a non-relativistic superfluid is deprived.
We present the general formulation of the relativistic fluid dynamics with vorticity (including relativistic superfluid) on a manifold with boundary. Making use of the Hodge decomposition, we emphasize that the equations of motion include a term due to non-trivial topology, while the pure vortex term introduced by Carter and Langlois will be presented merely by a co-exact form. We also consider a vortex sheet combined of individual vortices and discuss the boundary problem.
We consider the discontinuities in a two-constituent relativistic superfluid. In the acoustic limit they degenerate into the first and second sound which are independent up to the second-order linear approximation. Inclusion of the quadratic deviations relates to the small-amplitude shock. Particularly we consider a plane shock at low temperature when the phonon excitations contribute to the normal constituent. So we found the generalization of the temperature increment and acoustic wave velocity in relativistic superfluid. The fourth sound speed is also calculated.
Instead of the infinitesimal extrinsic and intrinsic perturbations on strings, considered so far, we discuss the evolution and propagation of finite-amplitude perturbations. Those intrinsic perturbations may result in appearance of stable discontinuities similar to the shock waves.
A particular example of chaos can be conceived in the interaction of non-linear oscillator with a harmonic gravitational wave. When we replace the linear potential forces by the therm SIN(x), the type of solution becomes subject to external perturbation. Although the perturbation produced by the gravitational wave is weak the standard estimations allow to predict the appearance of chaos at definite range of parameters. This qualitative change in the character of motion immediately detects the fact of impact with gravitational wave. Another advantage relates to a broad range of frequencies so that the narrow resonance band is not required.
An attempt is made to explain the 8-second periodicity of the 5th March 1979 soft gamma-ray repeater as a consequence of the elastic wave precession in the rigid crust of the rotating neutron star.