[en] This book presents those achievements of relativistic astrophysics which are well established through observation. It provides an account of major developments in cosmology, black holes, gravitational waves and other fields where relativity theory and astrophysics meet. Contents: Preface. Gravitational fields. Elements of relativistic thermodynamics and hydrodynamics. Gravitational fields in matter. Stellar equilibrium and stability in general relativity. Rotating stars. Neutron stars and pulsars. Gravitational collapse and black holes. Astrophysics of neutron stars and black holes. Gravitational waves. Cosmology. Appendix

[en] Conditions under which a vacuum type-D space-time admits a regular S₂ separability structure are investigated. It is shown that all vacuum type-D space-times without acceleration admit such a structure. It turns out that the structure is completely determined by the Killing tensor and the metric. (author)

[en] The authors investigate static, spherical configurations of cold catalized matter in the Einstein-Cartan theory of gravitation. Assuming that density of spin is proportional to the number density of baryons n and using an equation of state of degenerate, relativistic Fermi gas, the relativistic equation of equilibrium is integrated numerically. Also the authors study the stability of those configurations. Configurations with central number density nsub(c) such that d(p tilde)/dn/sub(n=nsub(c))>0, where p tilde is the effective pressure, are very similar to general relativistic configurations with the same central density. In the Einstein-Cartan theory there exists another disjoint of equilibrium configurations for which d(p tilde)/dn/sub(n=nsub(c))<0 but ptilde(n=nsub(c))>0. Those configurations have very small masses approximately 10^-6 g and radii approximately 10^-34 cm and are unstable. (Auth.)

[en] We describe a method of generating stationary asymptotically flat solutions of the Einstein-Maxwell equations starting from a stationary vacuum metric. As a simple example, we derive the Kerr-Newman solution. (author)

[en] It is a review of present status of observations and theoretical interpretation of the cosmological background of electromagnetic radiation. Radiometric method of measuring very weak signals at microwave frequencies is described. Different explanations of the observed planckian spectrum and origin of the electromagnetic background radiation are presented and it is concluded that the cosmological explanation is the most plausible strongly supporting the hot big bang model. Physical processes leading to distortions in the blackbody spectrum of background radiation are discussed. (author)

[en] A stationary axially symmetric perturbation of a rotating black hole due to a distribution of test matter is investigated. The Newman-Penrose spin coefficient formalism is used to derive a general set of equations describing the perturbed space-time. In a linear approximation it is shown that the mass and angular momentum of a rotating black hole is not affected by the perturbation. The metric perturbations near the horizon are given. It is concluded that given a perturbing test fluid distribution, one can always find a corresponding metric perturbation such that the mass and angular momentum of the black hole are not changed. It was also noticed that when a tends to M, those perturbed spin coefficients and components of the Weyl tensor which determine the intrinsic properties of the incoming null cone near the horizon grow indefinitely. (author)

No abstract available

No abstract available

No abstract available

No abstract available