Paul J. Steinhardt

July 11, 2009

Paul J. Steinhardt is the Albert Einstein Professor of Science at Princeton University. He is on the faculty of both the Department of Physics and the Department of Astrophysical Sciences.

Steinhardt is one of the architects of the “inflationary model of the universe." This is a modification of the standard Big Bang picture, which proposes a brief period of extraordinary, superluminal expansion in the early universe to explain the homogeneity and large-scale structure of the universe. He and collaborators constructed the first successful model and then showed how quantum fluctuations generated during inflation may seed the formation of galaxies and also produce temperature variations in the cosmic microwave background.

In the last year, Steinhardt and Neil Turok (Cambridge University) proposed a radical alternative, "the cyclic universe." In this scenario, the universe avoids inflation and instead, undergoes an infinite time in the past and the future, going through an endless sequence of bangs and crunches.

Steinhardt has made numerous contributions to the study of dark matter and dark energy. Steinhardt and David Spergel (Princeton) developed the idea of “strongly iself-interacting dark matter” to explain observations of subgalactic structure. Steinhardt also introduced the concept of “quintessence” to explain the recently observed acceleration of the universe.

In condensed matter physics, Steinhardt and Dov Levine (Technion) predicted a new form of matter, known as a “quasicrystal." This is a solid that exhibits five-fold and other symmetries that are impossible for ordinary crystals. He pioneered studies of their physical and structural properties and is currently investigating their application to photonics. He has edited two books on the subject, The Physics of Quasicrystals and Quasicrystals: The State of the Art.

See essays by this author:
The Cyclic Universe