An exact solution corresponding to a relativistic charged fluid sphere is found. It is a generalisation of the metric found previously by Banerjee and Banerji for a spherically symmetric distribution of an electrically neutral fluid. The behaviour of the model is studied from the conditions of fit at the boundary with the Reissner Nordström metric. It is found that in some cases the model collapses, while in other cases a bounce occurs at a certain epoch of an initially contracting model.
A set of exact solutions of the gravitational field equations is investigated. The field equations are obtained by means of the Palatini method from a Lagrangian which, apart from the usual terms \({\cal {L}}_E = (1/2) \sqrt {-g}R\), contains all possible quadratic terms. The vacuum equations as well as those corresponding to null fluid and continuous medium are considered. The method of holonomy groups and the corresponding classification of pseudoriemannian four-dimensional spaces are used.
Within the framework of the Jost–Lehmann–Dyson (JLD) representation and the renormalization-group (RG) equation, it is shown that either the RG technique is not applicable to deep-inelastic phenomena or Regge behaviour and Bjorken scaling for structure functions do not coexist.
The classical electromagnetic current can be a Lorentz invariant vector field. On the other hand, the electromagnetic field cannot be a Lorentz invariant field. Therefore, the field generated by a Lorentz invariant current must have a deviation from the perfect Lorentz symmetry which is not implicit in the current. It is possible to choose the deviation in such a way that its existence cannot be detected by means of experiments with classical test particles.
Narrow signals are observed in the effective mass spectra of “pp” and “pn” systems at \(Q \approx 0\) MeV in the deuteron break up reaction. Experimental evidence is presented for a spin-dependent interaction in the elementary pn \(\to \) np charge exchange process.
Predictions of the statistical quark model are compared with existing data on multiplicity distributions of nucleon–antinucleon annihilation at rest. Reasonable agreement is found for both p\(\overline {\rm p}\) and n\(\overline {\rm p}\) annihilations.
Angular distributions of spectator nucleons in collisions of high-energy particles with deuterium nuclei are discussed in the framework of the impulse model. Comparison with experimental data shows that predictions following from this simple theoretical model are verified by experiment. Some general remarks on the study of angular distributions of spectator nucleons are given.
The sine Gordon field in \(3 + 1\) dimensions is studied as an example of a quantum field theory with persistent self interactions. Exact, positive or negative frequency (solitary wave) solutions of the sine Gordon equation containing either annihilation or creation operators of the linear field theory are discussed. The sine Gordon solitary wave propagator closely resembles the solitary wave propagator of the \(\lambda \phi ^4\) theory.
A semi-phenomenological analysis of high energy collisions of loosely bound composite particles suggests introducing form factors whose analytic form depends on the reference frames privileged by the structure of the wave functions of such particles. Cross-sections of elastic scattering and disintegration processes of composite particles are discussed as possible tests of the proposed scheme.
