Accreting black holes and neutron stars at luminosities above 0.01 of the critical Eddington luminosity have a lot of similarities, but also drastic differences in their radiation and power density spectra. The efficiency of energy release due to accretion onto a rotating neutron star usually is higher than in the case of a black hole. The theory of the spreading layer on the surface of an accr...

We study the spin evolution of X-ray neutron stars in binary systems, which are being spun up by mass transfer from accretion disks. Our investigation reveals that a quark phase transition resulting from the changing central density induced by the changing spin, can lead to a pronounced peak in the frequency distribution of X-ray neutron stars. This finding provides one of several possible expl...

Massless neutrino exchange leads to a new long-range force between matter. Recently, it was claimed both that the potential energy due to this interaction i) dominates the total energy of neutron stars and ii) that it is zero. We recalculate the energy of a neutrino propagating in a classical, uniform background of neutrons and find a negligible, but non-zero contribution to the total energy of...

We report on numerical results from an independent formalism to describe the quasi-equilibrium structure of nonsynchronous binary neutron stars in general relativity. This is an important independent test of controversial numerical hydrodynamic simulations which suggested that nonsynchronous neutron stars in a close binary can experience compression and even collapse prior to the last stable ci...

In the inner crust of a neutron star, due to the high density and pressure, nuclei which are still present, are immersed in a neutron superfluid. One then expects that the dynamical properties of nuclei are significantly affected. In order to estimate the magnitude of the effect associated with the presence of a superfluid medium, we formulate the hydrodynamical approach to the nuclear dynamics...

The neutron capture cross section of the unstable nucleus W has been derived from experimental photoactivation data of the inverse reaction W(γ,n)W. The new result of σ = (687 ± 110)mbarn confirms the theoretically predicted neutron capture cross section of W of σ ≈ 700mbarn at kT = 30keV. A neutron density in the classical s-process of nn = (3.8 +0.9 −0.8) × 10 8 cm is derived from the new dat...