Alexander Vilenkin

Alexander Vilenkin, Russian Александр Виленкин, transcription Alexander Wilenkin, ( born May 13, 1949 in Kharkiv, Ukraine) is a Russian- American theoretical physicist who deals with cosmology.

Vilenkin studied physics at the University of Kharkov, where he made also in 1971 his diploma, but it was for political reasons (he is a Jew, which hampered their academic careers and study in the former Soviet Union, and refused with the KGB work ) excluded from further studies. He then did his military service and made ​​his way as a laborer, including as a night watchman at the zoo. In 1976 he emigrated via Italy to the United States, where he received his doctorate in 1977 at the State University of New York at Buffalo. As a post - graduate student, he was the 1977/78 Case Western Reserve University. From 1978 he was at Tufts University, in 1979 as Assistant Professor. He is since 1987 Professor of Physics and since 1989 director of the Institute of Cosmology. 1992 he worked as Fairchild Scholar at the California Institute of Technology.

Vilenkin is known for his idea of ​​"Eternal Inflation " ( Eternal Inflation, 1983) and the quantum-mechanical generation of the universe out of nothing (1982). These tunnels solution (from a universe of radius 0, ie, the "nothing" to a finite radius) of the path integral formulation of quantum gravity was simultaneously developed an alternative to "no boundary proposal" by James Hartle and Stephen Hawking. Vilenkin also showed that in its solution, in contrast to that of Hawking and Hartle inflation is likely. In his theory of eternal inflation, he argues that in almost all inflationary cosmological solutions in a kind of chain reaction constant new universes are formed, an idea which appends also Andrei Linde. With his student Arvind Borde, he showed that these models in the past must have a singularity. In the 2000s he developed with Jaume Garriga from the concept of an infinite number of parallel universes existing ( multiverse theory ) in which any kind of possible history is realized (because their number is finite ), and that infinitely often, "many worlds in one ". In contrast to similar previous many-worlds interpretation of quantum mechanics they are not superpositions of wave functions. The special position of our universe is given by Vilenkin from the anthropic principle. Using a variant of this principle ( principle of mediocrity called them ) said Vilenkin 1995 a non-zero value of the cosmological constant vorauszu a time when generally still a vanishing value was favored, before the discovery of the accelerated expansion of the universe. The now accepted value of the cosmological constant has according to his theory, a probability of 0.25.

Vilenkin also made ​​important contributions to the theory of cosmic strings, hypothetical filamentary concentrations of energy in cosmology, which could have played a role in the structure formation in the early universe.

He was Presidential Young investigator of the National Science Foundation ( 1984) and is a Fellow of the American Physical Society.

He has been married since 1973 and has one child.


  • (as Alex Vilenkin ): Cosmic Doppelgänger: How did the big bang - Like countless universes arise, Springer Verlag 2008, ISBN 3540739173 (Many worlds in one - in search for other universes Hill and Wang, 2006 ISBN 0809095238. )
  • With Paul Shellard: Cosmic strings and other topological defects, Cambridge University Press, 1994, 2000