abstract

The explicit form of the interior and exterior metric is found for a special but reasonable case of an inhomogeneous mass distribution in a thick plane plate.

abstract

The Einstein-Cartan theory of gravitation allows for avoiding singularities. This idea is supported by giving exact solutions of cosmological equations which are extensions of the Friedmannian cosmology. Various singularity-free models of dust and radiative universes are constructed. Two general relations are given which allow for a transition from dust-filled to radiation-filled universes with the same value of the scale factor. These relations are characteristic of the Einstein–Cartan theory, and cannot be brought over into general relativity. It is shown how exact solutions of the Einstein–Cartan theory can be derived from known solutions of general relativity. This procedure which may be applied to material spheres, is simple enough to generate a large set of useful solutions. Two examples are given.

abstract

The electromagnetic field of an arbitrary source distribution in Schwarzschild space time is given in linear approximation, using the technique of Green’s functions. For an oscillating dipole at infinity, the result is the generalized plane wave. This wave gives the usual deflection of light, and is the starting point for the exact solution of the problem of the diffraction of a plane wave at a Schwarzschild Black Hole.

abstract

The theory of electromagnetic plasma oscillations in the strong gravitational field is constructed by using relativistic kinetic Boltzman equations. In the atmosphere plasma of neutron stars damping decrement of transverse electromagnetic oscillations may be positive; in this case the electromagnetic oscillations increase, and plasma becomes unstable. This effect is discussed in its application to the pulsars model.

abstract

The first family of the flow-stationary and vortex-homogeneous solutions presented in Part 1 is investigated. Their symmetry group is shown to be 3-parametric, abelian and acting transitively on timelike hypersurfaces. Exterior solutions of the same symmetry are found and matched to the interior ones. The conformal curvature tensors are of Petrov type I, with one exception which is of Petrov type II. Matter filling the spacetime is shown to consist of co-axial cylinders rotating with different angular velocities. The redshift is found to be strongly anisotropic. The equation o1 state appears to result from the field equations.

abstract

A short survey of solutions of the Einstein field equations with rotating perfect fluid or dust as a source is given. It has the form of a table exhibiting all the coincidences between solutions found by different authors.

abstract

The differential cross section for the process \(\pi ^+\)n \(\to \) p\(\omega \) has been determined on the basis of the dynamical dual model of hadrons as proposed in an earlier paper. It is shown that the theoretical prediction is in excellent agreement with the experimental results. Also, it can nicely explain the fact that there is no dip in the differential cross section. Moreover, it is shown that the large value of the density matrix element \(\varrho _{00}\) in the Gottfried–Jackson frame, as observed in experiments, can be interpreted in a nice way.

abstract

Using the statistical model for charge branching ratios it is shown that the difference between the positive correlation between the numbers of charged and neutral pions produced in high energy non-annihilation processes and the corresponding negative correlation for annihilation processes just reflects the fact that the prong number distribution in annihilation processes is much narrower than in non-annihilation ones.

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In this paper we discuss three puzzles of the quark model, formulated recently by Lipkin and answered by him on the ground of the three-triplet quark model with eight vector gluons which had, in fact, already been solved some years ago in the three-triplet quark model with two vector gluons. The lower symmetry of the latter model is sufficient to answer Lipkin’s three questions but does not lead inevitably to the “symmetric quark model”.

abstract

A separable, quasirelativistic, potential model is used to describe \(\overline {K}\)N elastic and inelastic scattering. Free parameters of the model are set to reproduce the scattering data up to 300 MeV/\(c\) momentum and the virtual Y\(_0\)(1405) bound state energy and width. Various inelastic processes occurring below the \(\overline {K}\)N threshold and observed in the kaon nuclear interactions are studied. The dependence on the phenomenological parameters is discussed.

abstract

The paper contains an investigation of Bargmann transformations of free relativistic Green’s functions. We prove the equivalence of two types of triplets on the space of entire analytic functions. We present explicit analytic expression for the Bargmann transformation of free field propagators in one-dimensional case with any value of the mass parameter. In four-dimensional Minkowski space we derive Bargmann transformations for massless particles. In the case of massive particles it has been shown that the Bargmann transformations can be obtained in the form of power series representing entire functions. An analytic representation of the unitarity and causality conditions is given and the invariance of the growth and type with respect to Poincaré transformations is shown.

abstract

A new summation technique in perturbation theory is developed. By means of rearrangement of the ordinary perturbation expansion we can regroup terms with respect to order of correlation. The various correlations partially factorize from the rest which is totally factorizable. This factorization makes the series summable to infinite order in the coupling constant.

abstract

Stiffness and mass parameters as well as the energies of the vibrational states in some actinide nuclei have been calculated. Only quadrupole and hexadecapole degrees of freedom have been included. The calculations have been performed in the vicinity of the first minimum of the energy surface, by making use of three different approaches: Mottelson–Nilsson–Bés–Szymański, Strutinsky and microscopic ones. The results obtained in the calculations have been compared.

abstract

Differential cross sections for \(^{27}\)Al(p,p\(^{\prime }\))\(^{27}\)Al have been measured at 9.6 MeV in the range 25\(^{\circ }\)–150\(^{\circ }\) for the inelastic proton groups corresponding to 17 excited states of Al. The energy resolution was about 70 keV. It is shown that, similarly to the results obtained previously by other authors for 9 MeV neutrons, DWBA+Hauser–Feshbach calculation does not reproduce the experimental angular distributions nor can it explain the observed CN reduction factors. Possible reasons for the observed discrepancies are discussed.

abstract

The contribution of the short-range \({\mit \Lambda }\)NN correlations to the binding energy of a \({\mit \Lambda }\)-particle in nuclear matter, \(B_{{\mit \Lambda }3}\), is calculated with the help of the simplified method applied originally by Moszkowski in the pure nuclear matter problem. For the recent phenomenological \({\mit \Lambda }\)N potentials of Herndon and Tang, we obtain \(B_{{\mit \Lambda }3}\simeq -4\) MeV.

abstract

Reactions involving the formation and decay of compound nuclei with excitation energies up to 140 MeV have been studied. It was shown that cross section for compound nucleus formation was about 20% of the total one. The decrease in the cross section is discussed in terms of the effect of the angular momentum on the reaction mechanism. The excitation functions of reactions with 3 to 12 neutrons evaporated from the compound nucleus are compared with the predictions of the statistical model. The mass and isotope distributions of the fission products in reactions of uranium with carbon ions of different energies have been maesured. The results obtained are discussed from the point of view of the reaction mechanism and possibilities of synthesizing isotopes.