Arvin Borde

The 1994 Borde-Vilenkin Proof

Arvin Borde (Kavli Institute of Theoretical Physics at the University of California Santa Barbara) and Alexander Vilenkin (Director of the Institute of Cosmology at Tufts University) formulated a proof in 1994 that every inflationary universe meeting five assumptions would have to have a singularity (a beginning of the universe/multiverse in a finite proper time)^[1]. Our universe meets all the conditions in this proof. In 1997 they discovered a possible exception to one of their assumptions (concerning weak energy conditions) which was very, very unlikely within our universe. Physicists, including Alan Guth (the Victor Weisskopf Professor of Physics at the Massachusetts Institute of Technology, and father of inflationary theory) did not consider this exception to be relevant: “… the technical assumption questioned in the 1997 Borde-Vilenkin paper does not seem important enough to me to change the conclusion [that the 1994 proof of a beginning of inflationary model universes is required].”^[2] Therefore, the 1994 proof still has general validity today. (Refer to NPEG Chapter One, Section IV.D)