Probe particle motion in a Schwarzschild field

The motion of probe particles and light beams in a specified Schwarzschild metric is considered for the full range of radial coordinate r: 0 r . The singularity at r=r^g is elininated by shifting the integration contour to the complex plane [4, 5, 6]. There is then possible a class of finite motions with particle passage through the center. Light rays emitted by the probe particle during such motion are constructed, and difficulties with the causality principle occurring in both the T- and R-regions are evaluated.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 44–50, October, 1977.