The Physical Structure of the Energy-Momentum Tensor in General Relativity.

Available from UMI in association with The British Library. The physical structure of the energy-momentum tensor is of great importance in General Relativity. In the last few years many people have discussed various aspects of this subject. The present study discusses some of the algebraic and geometric interpretations of these physical structures. It will be shown how a systematic use of the theory of the classification of energy-momentum tensors greatly simplifies many problems. In chapter one, the basic equations of General Relativity will be introduced and a notation will be laid down. In chapter two, a brief summary of the classification of the Weyl tensor and energy-momentum tensor will be given. The well-known energy conditions will be introduced here and their algebraic restrictions on the energy-momentum tensor given. In chapter three, the energy-momentum tensor corresponding to various combinations of physical fields will be given, discussed and classified. A comprehensive study of the energy-momentum tensor of a general viscous fluid with heat flow will also be given. A uniqueness problem arises in the physical interpretation of some of these energy -momentum tensors and this is studied in detail in chapter four. Chapter five studies the problem of the inheritance of metric symmetries in the energy-momentum tensor. The algebraic classifications given in chapters two and three lead to a convenient solution of this problem. Finally, chapter six shows how the Segre type classification of the energy-momentum tensor leads to a simple electromagnetic analogue of the well-known vacuum "Peeling" theorem. Chapters three, four, five and six contain the bulk of the new results contained in this thesis.