Paul Steinhardt
Encyclopedia
Paul J. Steinhardt is the Albert Einstein
Professor of Science at Princeton University
and a professor
of theoretical physics
. He received his B.S. at the California Institute of Technology
and his Ph.D. in Physics at Harvard University
. He was a Junior Fellow in the Harvard Society of Fellows
and Mary Amanda Wood Professor of Physics at the University of Pennsylvania
before joining the faculty at Princeton University
in 1998. He is currently the Director of the Princeton Center for Theoretical Science.
He is best known for his work in theoretical cosmology
, where he helped develop the theory of cosmic inflation
, which attempts to explain the homogeneity and geometry of the universe and the origin of the fluctuations that seeded the formation of galaxies and large-scale structure. He introduced the concept of quintessence
, a time-varying form of dark energy
to explain the current accelerating expansion of the universe. His recent work has been on brane cosmology
, especially the ekpyrotic and cyclic
models. The cyclic theory of the universe is a radical alternative to big bang/inflationary cosmology in which the evolution of the universe is periodic and the key events shaping the large scale structure of the universe occur before the big bang.
Steinhardt also works in condensed matter physics
, where he coined the name quasicrystal
, a novel phase of matter which has symmetries forbidden to ordinary periodic crystal
s. He has made numerous contributions to understanding their mathematical and physical properties. Recently, he has helped develop a photonic quasicrystal (the quasicrystal analogue of a photonic crystal
) for efficiently trapping and manipulating light in selected wavebands.
He is a Fellow in the American Physical Society
and a member of the National Academy of Sciences
. He received the P.A.M. Dirac Medal from the International Centre for Theoretical Physics
in 2002 for his contributions to inflationary cosmology and the 2010 Oliver Buckley Prize from the American Physical Society for his work on quasicrystals.
Albert Einstein
Albert Einstein was a German-born theoretical physicist who developed the theory of general relativity, effecting a revolution in physics. For this achievement, Einstein is often regarded as the father of modern physics and one of the most prolific intellects in human history...
Professor of Science at Princeton University
Princeton University
Princeton University is a private research university located in Princeton, New Jersey, United States. The school is one of the eight universities of the Ivy League, and is one of the nine Colonial Colleges founded before the American Revolution....
and a professor
Professor
A professor is a scholarly teacher; the precise meaning of the term varies by country. Literally, professor derives from Latin as a "person who professes" being usually an expert in arts or sciences; a teacher of high rank...
of theoretical physics
Theoretical physics
Theoretical physics is a branch of physics which employs mathematical models and abstractions of physics to rationalize, explain and predict natural phenomena...
. He received his B.S. at the California Institute of Technology
California Institute of Technology
The California Institute of Technology is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering...
and his Ph.D. in Physics at Harvard University
Harvard University
Harvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...
. He was a Junior Fellow in the Harvard Society of Fellows
Harvard Society of Fellows
The Harvard Society of Fellows is a group of scholars selected at the beginning of their careers by Harvard University for extraordinary scholarly potential, upon whom distinctive academic and intellectual opportunities are bestowed in order to foster their individual growth and intellectual...
and Mary Amanda Wood Professor of Physics at the University of Pennsylvania
University of Pennsylvania
The University of Pennsylvania is a private, Ivy League university located in Philadelphia, Pennsylvania, United States. Penn is the fourth-oldest institution of higher education in the United States,Penn is the fourth-oldest using the founding dates claimed by each institution...
before joining the faculty at Princeton University
Princeton University
Princeton University is a private research university located in Princeton, New Jersey, United States. The school is one of the eight universities of the Ivy League, and is one of the nine Colonial Colleges founded before the American Revolution....
in 1998. He is currently the Director of the Princeton Center for Theoretical Science.
He is best known for his work in theoretical cosmology
Physical cosmology
Physical cosmology, as a branch of astronomy, is the study of the largest-scale structures and dynamics of the universe and is concerned with fundamental questions about its formation and evolution. For most of human history, it was a branch of metaphysics and religion...
, where he helped develop the theory of cosmic inflation
Cosmic inflation
In physical cosmology, cosmic inflation, cosmological inflation or just inflation is the theorized extremely rapid exponential expansion of the early universe by a factor of at least 1078 in volume, driven by a negative-pressure vacuum energy density. The inflationary epoch comprises the first part...
, which attempts to explain the homogeneity and geometry of the universe and the origin of the fluctuations that seeded the formation of galaxies and large-scale structure. He introduced the concept of quintessence
Quintessence (physics)
In physics, quintessence is a hypothetical form of dark energy postulated as an explanation of observations of an accelerating universe. It has been proposed by some physicists to be a fifth fundamental force...
, a time-varying form of dark energy
Dark energy
In physical cosmology, astronomy and celestial mechanics, dark energy is a hypothetical form of energy that permeates all of space and tends to accelerate the expansion of the universe. Dark energy is the most accepted theory to explain recent observations that the universe appears to be expanding...
to explain the current accelerating expansion of the universe. His recent work has been on brane cosmology
Brane cosmology
Brane cosmology refers to several theories in particle physics and cosmology motivated by, but not exclusively derived from, superstring theory and M-theory.-Brane and bulk:...
, especially the ekpyrotic and cyclic
Cyclic model
A cyclic model is any of several cosmological models in which the universe follows infinite, self-sustaining cycles. For example, the oscillating universe theory briefly considered by Albert Einstein in 1930 theorized a universe following an eternal series of oscillations, each beginning with a...
models. The cyclic theory of the universe is a radical alternative to big bang/inflationary cosmology in which the evolution of the universe is periodic and the key events shaping the large scale structure of the universe occur before the big bang.
Steinhardt also works in condensed matter physics
Condensed matter physics
Condensed matter physics deals with the physical properties of condensed phases of matter. These properties appear when a number of atoms at the supramolecular and macromolecular scale interact strongly and adhere to each other or are otherwise highly concentrated in a system. The most familiar...
, where he coined the name quasicrystal
Quasicrystal
A quasiperiodic crystal, or, in short, quasicrystal, is a structure that is ordered but not periodic. A quasicrystalline pattern can continuously fill all available space, but it lacks translational symmetry...
, a novel phase of matter which has symmetries forbidden to ordinary periodic crystal
Crystal
A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...
s. He has made numerous contributions to understanding their mathematical and physical properties. Recently, he has helped develop a photonic quasicrystal (the quasicrystal analogue of a photonic crystal
Photonic crystal
Photonic crystals are periodic optical nanostructures that are designed to affect the motion of photons in a similar way that periodicity of a semiconductor crystal affects the motion of electrons...
) for efficiently trapping and manipulating light in selected wavebands.
He is a Fellow in the American Physical Society
American Physical Society
The American Physical Society is the world's second largest organization of physicists, behind the Deutsche Physikalische Gesellschaft. The Society publishes more than a dozen scientific journals, including the world renowned Physical Review and Physical Review Letters, and organizes more than 20...
and a member of the National Academy of Sciences
United States National Academy of Sciences
The National Academy of Sciences is a corporation in the United States whose members serve pro bono as "advisers to the nation on science, engineering, and medicine." As a national academy, new members of the organization are elected annually by current members, based on their distinguished and...
. He received the P.A.M. Dirac Medal from the International Centre for Theoretical Physics
International Centre for Theoretical Physics
The Abdus Salam International Centre for Theoretical Physics was founded in 1964 by Pakistani scientist and Nobel Laureate Abdus Salam after consulting with Munir Ahmad Khan. It operates under a tripartite agreement among the Italian Government, UNESCO, and International Atomic Energy Agency...
in 2002 for his contributions to inflationary cosmology and the 2010 Oliver Buckley Prize from the American Physical Society for his work on quasicrystals.
Publications
- P. J. Steinhardt and N. Turok, A cyclic model of the universe, Science 296, 1436(2002) arXiv:hep-th/0111098.
- P. J. Steinhardt and N. Turok, Endless Universe: Beyond the Big Bang, (Doubleday, 2007)
- J. Khoury, B. A. Ovrut, P. J. Steinhardt and N. Turok, "The ekpyrotic universe: Colliding branes and the origin of the hot big bang", Phys. Rev. D 64, 123522 (2001) arXiv:hep-th/0103239.
- D. N. Spergel and P. J. Steinhardt, "Observational evidence for self-interacting cold dark matter", Phys. Rev. Lett. 84, 3760 (2000) arXiv:astro-ph/9909386.
- N. A. Bahcall, J. P. Ostriker and P. J. Steinhardt, "The Cosmic Triangle: Revealing the State of the Universe", Science 284, 1481 (1999) arXiv:astro-ph/9906463.
- R. R. Caldwell, R. Dave and P. J. Steinhardt, "Cosmological Imprint of an Energy Component with General Equation-of-State", Phys. Rev. Lett. 80, 1582 (1998) arXiv:astro-ph/9708069.
- P. J. Steinhardt and S. Ostlund, The Physics of Quasicrystals (World Scientific, Singapore, 1987).
- J. M. Bardeen, P. J. Steinhardt and M. S. Turner, "Spontaneous Creation Of Almost Scale-Free Density Perturbations In An Inflationary Universe," Phys. Rev. D 28, 679 (1983).
- A. Albrecht and P. J. Steinhardt, "Cosmology For Grand Unified Theories With Radiatively Induced Symmetry Breaking," Phys. Rev. Lett. 48, 1220 (1982).