**Publication date:** Mar 1983

**Abstract:**

Due to the present indications of the existence of a non-zero

cosmological constant, some aspects of the influence of a Lambda not

equal to zero on the character of test-particle motion in black-hole

backgrounds are discussed. Equations of motion of electrically charged

particles and magnetic monopoles are written in the most general

Kerr-Newman-de Sitter dyon background. For the Kerr-de Sitter spacetime,

the latitudinal motion is examined in detail by using the ‚Chinese

boxes‘ technique. The radial motion in the Schwarzschild-de Sitter

background is considered with attention devoted to the existence and

stability of circular orbits and to the properties of purely radial

trajectories. Finally, the possibility of constructing an

Einstein-Strauss-de Sitter model of the Universe (i.e. a model of

Schwarzschild-de Sitter condensations in the Friedman Universe with a

non-zero Lambda-term) is discussed.

**Authors:**

Stuchlik, Z.;