abstract

In some recent papers it has been stated that the Gödel space-time may be generalized to the non-stationary case, simply by allowing the scale-factor to be a function of cosmic time. We here show (for rather general energy-momentum tensors) that this metric allows no solution of Einstein’s gravitational field equations.

abstract

The hypothetical de Brogue waves of the scalar bradyons and tachyons are considered. To describe them a new variant of the Klein–Gordon equation is proposed. For tachyons, it leads to unexpected freedom in choosing a variable scalar quantity and a constant four-vector. The former takes the place of the “rest mass” in the tachyon Theory, while the latter corresponds to the tachyon shock wave and expresses the tachyon-vacuum interaction. The resulting image of the tachyon differs from that usually accepted in special relativity and corresponds to that given by general relativity.

abstract

For the case of one-particle irreducible, separable divergent Feynman diagrams the classical definition of the \(\hat R\)-operation is compared with some intuitive approach to the problem of overlapping ultraviolet divergences. The freedom of the generalized \(\hat R\)-operation is analysed.

abstract

Examples of non-Abelian adiabatic connections derived from \(4 \times 4\) matrix Hamiltonians are presented. We find a multimonopole type non-Abelian connection.

abstract

The standard model weak corrections to the process \(e^+e^- \to \bar \nu \nu \gamma \) which are important from the point of view of consistent renormalization are calculated. The calculations of the hard bremsstrahlung corrections to the process are done and they are found to be in good agreement with the former results.

abstract

The gas of noninteracting strings is a very crude approximation to the description to a multistring system. This approximation has been used to discuss string models of the big bang and of the last stages of black hole evaporation. We review the thermodynamics of the gas of nonniteracting strings, which are an unusual thermodynamic system, because the density of states instead of growing as a power of energy explodes exponentially.

abstract

A question is considered, whether there might exist a new Abelian vectorlike gauge force, stronger than the electromagnetic one, that could still be hidden from us in the structure of matter, more precisely, in the structure of quarks which would be then composite. The Abelian character of such a hypothetical force may open wide experimental perspectives. At low energies, the main consequence of this force would be a new magnetic-type spin-spin interaction of nucleons (stronger than the magnetic one) which could manifest itself (even macroscopically) in polarized nucleon systems.

abstract

The differential cross sections of \(^{60}\)Ni(n,p) reaction were measured at \(E_{\rm n} = 17.3\) MeV. The results of this and previous investigations of \(^{58,60}\)Ni(n,p) reactions at \(E_{\rm n}\) close to 20 MeV are discussed in terms of the F.K.K. theory and the Geramb model. The determined and calculated total proton emission cross sections are compared.

abstract

Multiplicity distributions in rapidity bins are studied in the Marchesini–Webber model for \(e^+e^-\) annihilation. The intermittent, power-like growth of the scaled factorial moments for small rapidity bins is found. Corrections accounting for the rapidity dependence of the single particle density are analyzed and shown to lead to the universal behaviour for various choices of the studied rapidity range.