During the first decades after Einstein had developed his Theory of General Relativity, the main effort was to understand the theory and verify it experimentically. Meanwhile Genral Relativity is one of the experimentally best confirmed theories and has become a powerful tool for the investigation of cosmic processes where strong gravitational fields are involved.
This book contains 16 contributions from well-known experts giving a broad overview for non-specialists who want to learn how to purely academic issues like gravitational wave detectors are now put into reality.

This volume is published in honor of Friedrich Hund's 100th birthday. It is a modern review on matter at high densities and pressures in astrophysics from Hund's early contribution to present-day ideas. The relation between the equation of state and the structure of compact cosmic objects is discussed, and two main contributions deal with the equation of state of baryonic matter at nuclear densities and with the numerical solution of the general relativistic field equations for non-rotating and rapidly rotating neutron stars. In a final chapter the present state of asteroseismology is presented as a tool to explore the interior of cosmic objects by analyzing the observed free oscillations of the Earth, the Sun, and white dwarf stars.