Daniel Friedan

Daniel Harry Friedan (* October 1948 ) is an American theoretical physicist.

Friedan is the son of Betty Friedan. In his youth he composed. He studied literature and philosophy, but then switched to physics. Friedan in 1980 his doctorate at the University of California, Berkeley ( Nonlinear models in dimensions ). After that, he was at the French nuclear research center in Saclay and from 1981 at the University of Chicago ( Enrico Fermi and James Franck Institute of Physics ). Since 1989 he is a professor at Rutgers University at New High Energy Theory Center.

Friedan is known for his work on conformal field theories in the 1980s with applications in string theory and statistical mechanics, some with Zongan Qiu and Stephen Shenker. It was based on ideas of Polyakov ( path integral description of Strings 1981) for string theory and of Polyakov, Belavin and Zamolodchikov (1983 ) on conformal field theories. Friedan, Qiu and Shenker showed that the condition of unitarity ( which occur at most in statistical mechanics applications conformal field theories is present ) to severe restrictions of conformal field theories (discrete series) leads.

Friedan also belonged to the leading string theorists. Most recently, he was critical string theory, which he considers to be a failure, because it allows a number of background spacetimes and the physics at large length scales can not predict. Instead, he suggested a non-linear theory before (lambda model, the same theory that he had examined in his thesis ) to describe the usual quantum field theory for large lengths.

In a work from 1984, he led independently by Luis Alvarez- Gaume from the Atiyah-Singer index theorem using methods of supersymmetry.

In 1987 he was MacArthur Fellow. In 2010 he was awarded the Lars Onsager - Prize for fundamental work of the classification and characterization of two-dimensional conformal field theories with unitary Shenker.