This book discusses some of the open questions addressed by researchers in general relativity. Photons and particles play important roles in the theoretical framework, since they are involved in analyzing and measuring gravitational fields and in constructing mathematical models of gravitational fields of various types. The authors highlight this aspect covering topics such as the construction of models of Bateman electromagnetic waves and analogous gravitational waves, the studies of gravitational radiation in presence of a cosmological constant and the gravitational compass or clock compass for providing an operational way of measuring a gravitational field. The book is meant for advanced students and young researchers in general relativity, who look for an updated text which covers in depth the calculations and, equally, takes on new challenges. The reader, along the learning path, is stimulated by provocative examples interspersed in the text that help to find novel representations of the uses of particles and photons.

This book is aimed at students making the transition from a first course on general relativity to a specialized subfield. It presents a variety of topics under the general headings of gravitational waves in vacuo and in a cosmological setting, equations of motion, and black holes, all having a clear physical relevance and a strong emphasis on space-time geometry. Each chapter could be used as a basis for an early postgraduate project for those who are exploring avenues into research in general relativity and who have already accumulated the required technical knowledge. The presentation of each chapter is research monograph style, rather than text book style, in order to impress on interested students the need to present their research in a clear and concise format. Students with advanced preparation in general relativity theory might find a treasure trove here.

The book is about exact space-time models of the gravitational fields produced by gravitational radiation. The authors' extensive work in the field is reviewed in order to stimulate the study of such models, that have been known for a long time, and to highlight interesting physical aspects of the existing models in some novel detail. There is an underlying simplicity to the gravitational radiation studied in this book. Apart from the basic assumption that the radiation has clearly identifiable wave fronts, the gravitational waves studied are directly analogous to electromagnetic waves. The book is meant for advanced students and researchers who have a knowledge of general relativity sufficient to carry out research in the field.