We investigate the dynamics of a spherically symmetric distribution of matter, in the circumstance that we allow creation of matter in the Lyttleton–Bondi sense, on the basis of Einstein’s field equations for the adiabatic case with non-vanishing internal pressure gradient. It has been shown that if the density is uniform throughout the body at each instant (and so is a function of time only) and the motion is shear free, then either the sphere is static and has a definite charge distribution or it is non-static and continually expands.
In the framework of classical field theory, we look for the physical meaning of the “improved” energy-momentum tensor for a scalar field. We study the motion of a point-like particle interacting with a scalar field. Together with the “improved” energy-momentum tensor, we introduce a force, which depends on the velocity of the particle and is, if certain conditions are fulfilled, repulsive.
The paper gives a modification of a unified theory of gravitation and electromagnetism described previously by the author. The modification leads to a geometric interpretation of the electromagnetic potential \(A_{\mu }:A_{\mu }\) is proportional to \(h^5_{\mu }\), a component of the five-dimensional equivalent of a tetrad.
Approximate equations of motion are derived from gravitational field equations with higher derivatives. The approximation takes into account the selfinteraction force. The selfinteraction force coincides with the analogous force resulting from the Einstein field equations.
Two body pv hadronic decays of charmed baryons are studied using current algebra techniques in the SU(4) framework. Weak decay amplitudes are calculated with and without 15-admixture. We also include the antisymmetric representations in the weak Hamiltonian.
Taking the Breit equation at its face value we solve for parapositronium the corresponding radial equations with the Breit terms treated nonperturbatively. As expected from known perturbative arguments, the resulting fine-structure formula differs in the \(\alpha ^4\)-order from the familiar correct formula derived by treating the Breit terms in the lowest order only.
Relations between quark masses and weak mixing angles suggested by the assumption of sequential mass generation are discussed. A classification of these relations according to additional conditions needed for their derivation is presented. In this classification the relation \(\sin \theta _3/\sin \theta _2 \approx \sqrt {\frac {m_{\rm u}m_{\rm b}}{m_{\rm s}m_{\rm c}}}\) turns out to be singled out as the most direct consequence of the assumption of sequential mass generation.
We propose a (hopefully) empirical spectral formula for lepton and quark generations as they appear in the standard model. Then the top quark is predicted at about 20 GeV, while the charged lepton, up quark and down quark of the hypothetic fourth generation at 28.5\(\pm ^{0.2}_{0.5}\) GeV, at about 250 GeV and at about 62GeV, respectively.
