Eight carefully written articles on the interactions between the ideas and concepts of particle physics and those of astrophysics make up this book. Two long introductory lectures give a survey of modern concepts in particle physics and in astrophysics and cosmology, stressing features of common interest. The other six contributions deal with the physics of supernova explosions, with black holes, with neutrino oscillations, with the importance of phase transitions for the large-scale structure of the Universe, and with the use of the ideas of quantum gravity for computer simulations. These rather detailed review articles will be of value for many years to come. The book is intended for graduate students and researchers both in particle physics and in astrophysics.