When was the American theoretical physicist and cosmologist which Alexander Vilenkin worked with in 2013 born
Alexander Vilenkin Alexander Vilenkin (Russian: Алекса́ндр Виле́нкин ,Ukrainian: Олександр Віленкін ; 13 May 1949, Kharkiv, Ukraine, Soviet Union) is Professor of Physics and Director of the Institute of Cosmology at Tufts University. A theoretical physicist who has been working in the field of cosmology for 25 years, Vilenkin has written over 150 papers. Soon after Paul Steinhardt presented the first example of eternal inflation, Vilenkin showed that eternal inflation is generic. Working with Arvin Borde and Alan Guth, In 2003, he showed that a period of inflation has to have a beginning and there has to be a period that precedes it. This is a problem because, without a theory to explain the conditions before inflation, it is not possible to determine how likely it is for inflation ever to occur. Some considerations suggest that the probability is very small, resulting the "initial conditions problem.”
Alex Ignatiev Alex Ignatiev (born 1945) is an American physicist currently Distinguished Professor at University of Houston.