A Heavy-Light Quark Potential

In many studies of meson-baryon interactions with short one gluon exchange potential (OGEP), usually a full non-relativistic reduction, at the quark level Hamiltonian, is performed. In systems like [Formula: see text], light and heavy quarks are present, which in principle would require only a partial non-relativistic reduction. We shal start from a JKJ relativistic quark Hamiltonian and apply a partial non-relativistic reduction in order to obtain a OGEP between heavy and light quarks (heavy-light quark potential).

Possible Relativistic Definitions of Parallax, Proper Motion and Radial Velocity

It is argued that the relativistic definitions of parallax, proper motion and radial velocity consistent with an accuracy of 1 μas should be considered only within a well-defined algorithm of relativistic reduction of observational data. Such an algorithm is formulated and the corresponding definitions of astrometric parameters are discussed.

Relativistic Reduction of Astrometric Observations at Points Level of Accuracy

The framework of general relativity theory (GRT) is applied to the problem of reduction of high precision astrometric observations of the order of one microarcsecond. The equations of geometric optics for the non-stationary gravitational field of the Solar system have been deduced. Integration of the equations of geometric optics results in the isotropic geodesic line connecting the source of emission (a star, a quasar) and an observer. This permits to calculate the effects of relativistic aberration of light due to monopole and quadrupole components of the gravitational field of the Sun and the planets taking into account their motions and rotation. Transformations between the reference systems are used to calculate the light aberration occurring when passing from the satellite system to the geocentric system and from the geocentric system to the baryecntric system. The baryecntric components of the observed position vector reduced to the flat space-time are corrected, if necessary, for parallax and proper motion of a celestial object using the classical techniques of Euclidean geometry.