Symmetries and Curvature Structure in General Relativity (World Scientific Lecture Notes in Physics Vol 47)

This book is concerned with mathematical topics related to general relativity. Chapters 1-6 are expositions of a number of parts of mathematics which are important for relativists. The main subjects covered are linear algebra, general topology, manifolds, Lie groups and, in particular detail, the Lorentz group. Chapters 7-13 analyse aspects of the geometrical structure of spacetimes. They focus on symmetries of various types and on properties of curvature. Subjects covered include the Petrov classification, holonomy groups, the relation between metric and curvature, affine vector fields, conformal symmetries, projective symmetries and curvature collineations. This part of the book is a treatise on the (mainly local) geometry of four-dimensional Lorentz manifolds, with attention to energy-momentum tensors of interest in general relativity. In the first six chapters the author has concentrated on giving definitions and statements of theorems, the proofs being left to the references that are quoted. He has clearly put much effort into producing a very smooth exposition which is easy to follow and has succeeded in giving us a readable and informative account of the mathematics covered. At the same time mathematical rigour is strictly observed. He also takes the time to carefully discuss many of the subtleties which arise. This part of the book has the character of a textbook suitable for students of general relativity but experienced researchers will also find it a useful reference and are likely to come across interesting facts they have not met elsewhere. The remaining chapters are more like a research monograph and are influenced by the author’s own research interests. More proofs are included. Much of the material in this part will be of interest to a narrower audience of relativists than that of the first part. It should, however, be of interest to those working on exact solutions of the Einstein equations and related topics. It is also the case that most relativists are concerned with detailed properties of symmetries and curvature in some phases of their work and may find information which can help them in this book. Two examples of useful things to be found in this book for which it is difficult to find a comparable account elsewhere are the discussions of covering spaces and the subgroups of the Lorentz group. Section 3.10 treats covering spaces in a general topological context while section 4.14 shows how these ideas can be adapted to the smooth category. Section 6.4 lists all the connected subgroups of the Lorentz group and collects background information about these subgroups. I have no doubt that this book will be valuable for students taking courses in general relativity and for people preparing their PhD in the subject.