Velocity addition formulas in Robertson-Walker spacetimes

Universal velocity addition formulas analogous to the well-known formula in special relativity are found for four geometrically defined relative velocities in a large class of Robertson-Walker spacetimes. Explicit examples are given. The special relativity result is recovered as a special case, and it is shown that the spectroscopic relative velocity, in contrast to three other geometric relative velocities, follows the same addition law as in special relativity for comoving observers in Robertson-Walker cosmologies.Comment: 26 pages, 5 figure

Psychology in Education and Health IV. Proceedings of the IV Leipzig-Evora Scientific Meeting in Psychology

The Department of Psychology of University of Evora, the Institute for Psychology of University of Leipzig and University of Madeira organized jointly the IV Leipzig-Évora Scientific Meeting in Psychology | 1st International Scientific Meeting in Psychology. This volume contains the main contributions presented by scholars of Leipzig and Évora, as well as by guests from other universities.Papers on the application of Psychology in the fields of health, well-being, education, child development and clinical were discussed. The main areas of research and application in modern Psychology are here represented