[en] The problem of elastic matter in gravitational field having six parameter symmetry is studied by help of the more general theory of Carter and Quintana. The results are compared to the author's earlier calculations using the less general Rayner's formalism. It is shown that previous results remain valid if the equation of state is chosed specially. The Hookean limit of the two theories differ from one another but there is no essential difference between the behaviours of the solutions. (Sz.N.Z.)

[en] There is a wide-spread belief in the literature of relativistic astrophysics concerning nonsingular final states of the stellar evolution: the external gravitational field of a physically nonsingular central symmetric body (e.g. a neutron star) is asymptotically empty and simple, i.e. there are no closed or trapped light-like causal geodesics. Present paper shows that this belief is false: some examples are presented for nonsingular bodies with various equations of state, around which there are closed light-like trajectories: 'orbiting light'. The reality of the used equations of state is discussed in detail. Present state of particle physics does not establish the existence of matter with such equations of state, but the hypothetical subquark level of matter may have such equation of state, thus 'subquark-stars' may exist with orbiting light around them. So the criterion of 'nonsingularity' must be further analyzed and accurately defined. (D.Gy.) 24 refs.; 5 figs

[en] The possible effects of the nucleon-quark phase transition on the dynamics of heavy ion collisions are discussed. It is shown that the formation of the quark phase can be expected at recent experiments. Nevertheless, the compressibility of the two-phase mixture remains relatively low, thus the quark phase remains limited in both space and time, and the observables are not strongly affected. (author)

[en] Some estimations are made for the influence of the deuteron volume on the d/p ratio in dilute, hot deuteron-nucleon gases. The result is that in reasonable equations of state, this volume can imitate an 'entropy excess' similar to that in 0.4-0.8 GeV/nucleon heavy ion collisions, so it is possible that there is no excess at all. (author)

[en] In the paper the elastic Schwarzschild interior solution for spherically symmetric elastic matter is studied. It is shown that in the case of certain type of homogeneity (''material hcmogeneity'') the problem can be reduced to an ordinary non-linear differential equation, whose certain solutions describe finite spheres. The calculations are performed in the Rayner's formalism modified by Carter and Quintana. As an example the homogeneous model of the Earth is discussed. (Sz.N.Z.)

[en] The spatially symmetric electrovac problem is investigated in the General Relativity with common geodesic and shearing eigenrays. It is shown that all these solutions are Ernst counterparts of the corresponding vacuum solutions. (author)

[en] The conventional extension of the canonical quantization for the local field theories leads to serious mathematical and physical problems (ultraviolet catastrophes and instability of the vacuum). A new proposed method of this extension exploits maximally the principle of locality. Identical copies of the quantum counterparts of the classical mechanical system are placed at each points of a hyperspace of fixed time. The global system is synthetized by quantum statistical method. The argument of wave function, the field operator does not depend explicitely on the point of the space-time. In the perturbation theory the interaction Hamiltonian is now not global but local, thus the usual ultraviolet divergences do not appear. This formalism is an explicite example that the quantum dynamics of a system can be locally implemented, according to the physical measuring situation. (D. Gy.)

[en] An interesting task in general relativity is to look for external solutions of compact final states of stellar evolution, such as rotating neutron stars and black holes, when Newtonian treatment is already insufficient. The stationary vacuum problem with eigenray structure of κ=const and σ=const and nonzero is considered, as a possible Kerr generalisation. The result is that for the solutions of the Einstein equation this class is empty. (author) 11 refs

[en] In a simplified model the evolution of the originally nonthermal momentum distribution has been followed. The result is, that, although the final entropy deficiency may be quite substantial at 800 MeV/nucleon beam energy for smaller nuclei, the detected process does not reflect the extent of deviation from equilibrium (quite substantial). The reason is the addition of flow velocities, different in different volume elements. (author) 26 refs.; 11 figs

[en] Recent developments in the investigations connected with quantum field theory in curved spacetimes, the large scale structure of the Universe revealed a possible relevance of conformal analogous of the theory of general relativity. In such theories the role of Killing symmetries of the conventional Einstein theory is shifted to that of conformal Killing symmetries. In the paper it is supposed that a spacetime manifold admits a group of conformal symmetries and an answer is given to the question of the necessary and sufficient conditions the manifold and the generators has to fulfil in order that the manifold be conformally equivalent to a spacetime admitting the same group but of ordinary Killing symmetries. (Sz.N.Z.)