A Short Tour of the Universe Guided by Einstein and Others

Arvind Borde is Senior Professor of Mathematics, Physics, and Astronomy at Long Island University, Post. He graduated from Bombay University with a bachelor's degree in physics and mathematics, then received his PhD from the Institute for Theoretical Physics at the State University of New York, Stony Brook. Borde works on mathematical aspects of the theory of relativity, using the topological and geometrical tools introduced by Roger Penrose, Stephen Hawking, and Robert Geroch. He has proved theorems on topology change and on the focusing of light rays. He has concentrated especially on the large scale structure of spacetimes in inflationary models (extensions of the standard big bang model), and proved an important theorem with Alan Guth and Alexander Vilenkin that the inflationary multiverse had a beginning. His interest in topology led him and Rafael Sorkin to formulate the Borde-Sorkin conjecture on the conditions under which the topology of space can change while still preserving our ideas of causal continuity.