abstract

Equations of motion for a non-quantum-theoretical “photon” in curved spacetime are obtained by use of the Noether theorem relations and normal coordinates. Simple cases of photon world lines in certain gravitational fields are considered.

abstract

The present paper is concerned with the dynamics of the spinor wave fields in space-time with torsion. It is shown that torsion can both induce the minimal nonlinearity of the spinor equations and compensate it.

abstract

Time and space reflexions of spinors are investigated. It is assumed that the connection between spinors and null bivectors, discovered by Cartan and Whittaker, is valid in all reference frames. It follows that both time and space reflexions of spinors are antilinear operations and that there are two kinds of spinors, just as there are two kinds of Euclidean vectors. Penrose’s picture of a spinor on the sphere of complex numbers can be drawn only for one of the two spinors.

abstract

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.

abstract

It is proved that the discontinuity relation for the three-particle scattering amplitude in the total energy variable can be analytically continued in the external subenergy variables around the two-particle normal threshold branch points corresponding to these variables. Possible generalization to higher subsystem energies, i.e. towards higher number particle normal threshold cuts in the subenergy variables is outlined.

abstract

The introduction of \(b\)-universality into the additive quark model reduces the number of nonvanishing helicity amplitudes and offers an exact form of \(t\)-dependence for all amplitudes. Strong constraints on the additivity frame are obtained. Comparison with the data is made for the reaction \(\pi ^+p\to \pi ^0{\mit \Delta }^{++}\). The obtained results rule out the Gottfried–Jackson frame as the additivity frame.

abstract

The independent cluster emission model is unitarized by means of the Lippman–Schwinger equation. We study two possible generalizations of this model to processes involving the absorption of clusters. The first one (a) is of the type discussed by Auerbach, Aviv, Sugar and Blankenbecler, the second (b) is based on the generalization of Białas and Czyż. In case (a) we show that the introduction of energy and longitudinal momentum conservation does not change the general conclusions of the AASB paper — the leading singularity lies at \(J=l-{\mit \Lambda }/2\), \({\mit \Lambda }\) being the rapidity density of clusters produced by the input potential. In case (b) we show that diffractive production exists and is a direct consequence of energy and longitudinal momentum conservation.

abstract

Nuclear inertia] mass parameters corresponding to quadrupole and hexadecapole deformation are investigated. Two different approach are applied, both making use of the adiabatic approximation for the collective motion. The results are presented for \(^{240}\)Pu.