Singular potentials in relativistic equations of motion
It is shown that in relativistic equations of motion for a particle moving in external potentials some additional forces of purely relativistic origin appear. These forces are repulsive for scalar and pseudoscalar potentials thus preventing the particle from coming too near to the singularity of the potential in spite of its apparently attractive character. An adiabatic approximation to the interaction potential for two nucleons interacting through the pseudoscalar field is obtained. An interesting feature of this potential is a strong repulsive term acting at short distances between nucleons.
We search for the variable component of themagnetic field in γ Equ by studying four Nd III lines with the Main Stellar Spectrograph of the 6-m BTA telescope of the Special Astrophysical Observatory via accumulation and cyclic transfer of the electronic image of the Zeeman spectrum on the CCD. The single exposure time was set equal to 1/8 of the spectral variability period. We detected no variable component in the magnetic field of γ Equ with a period of 12.1 min in the November 5/6, 2003 observations.