Alan Guth, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
Andrei Linde, Stanford University, Stanford, California, USA
Paul Steinhardt, Princeton University, Princeton, New Jersey, USA
The 2002 Dirac Medal is awarded to Alan Guth, Andrei Linde and Paul Steinhardt for the development of the concept of inflation in cosmology. Although the history of the very early universe has not been firmly established, the idea of inflation has already had notable observational successes, and it has become the paradigm for fundamental studies in cosmology.
While the possibility of an exponential expansion of the early universe had been noted before, it was Guth who realized that inflation would solve some of the major problems confronting the big bang cosmology. Difficulties with the original inflationary model were recognized by Guth and others, and were overcome with the introduction of "new" inflation by Linde and Steinhardt (with Albrecht). Linde went on to propose other promising versions of inflationary theory, such as chaotic inflation. The greatest success of inflationary theory has been in accounting for the existence of inhomogeneities in the universe and predicting their spectrum, done by Guth (with Pi), Steinhardt (with Bardeen and Turner), as well as Hawking and Starobinsky.