Global Aspects in Gravitation and Cosmology

Global aspects in gravitation theory and cosmology are reviewed here to emphasize the basic theme that the very nature of gravitational force is such that global considerations of space-time are vital to understand this force in detail. Amongst the topics included are the structure and topology of space-time, exact solutions and singularities, quantum effects in strong gravity fields, and global upper limits in cosmology. Major open problems of significance are pointed out and the treatment here on the final fate of gravitational collapse shows that very strong-curvature naked singularities could result from the continual collapse of matter. This places important constraints on the formulation of the cosmic censorship hypothesis which is a crucial open question in relativistic astrophysics and the black hole physics.