Sean M. Carroll

For the biologist, see Sean B. Carroll.

Sean M. Carroll
Sean Carroll
Fields	Physics, Cosmology, Astrophysics, General Relativity
Institutions	California Institute of Technology
Alma mater	Harvard University (Ph.D.) Villanova University (B.S.)
Doctoral advisor	George B. Field
Doctoral students	Ignacy Sawicki
Influences	Albert Einstein, Ludwig Boltzmann

Sean Michael Carroll, Ph. D (born 5 October 1966) is a senior research associate in the Department of Physics at the California Institute of Technology. He is a theoretical cosmologist specializing in dark energy and general relativity. He is also a contributor to the physics blog Cosmic Variance, and has published in scientific journals and magazines such as Nature, Seed, Sky & Telescope, and New Scientist.

Described as a gifted science communicator, he has appeared on the History Channel's The Universe, Science Channel's Through the Wormhole with Morgan Freeman, and Comedy Central's The Colbert Report. Carroll is the author of Spacetime And Geometry, a graduate-level textbook in general relativity, and has also recorded lectures for the Teaching Company on cosmology and the physics of time. He is also the author of two popular books: one on the arrow of time entitled From Eternity to Here, and one on the Higgs boson entitled The Particle at the End of the Universe.

Career

Carroll received his Ph.D. in Astronomy and Astrophysics in 1993 from Harvard University, where his advisor was George B. Field. His dissertation's title is "Cosmological Consequences of Topological and Geometric Phenomena in Field Theories". He worked as a postdoctoral researcher at the Massachusetts Institute of Technology and Kavli Institute for Theoretical Physics at the University of California, Santa Barbara, and as an assistant professor at the University of Chicago until 2006 when he was denied tenure. He is now a research faculty member at Caltech.

His most-cited work, Is Cosmic Speed-Up Due To New Gravitational Physics?, was written with Vikram Duvvuri, Mark Trodden, and Michael Turner. With over 1,000 citations, it helped pioneer the study of f(R) gravity in cosmology.

In 2010, Carroll was elected as a Fellow of the American Physical Society, for "contributions to a wide variety of subjects in cosmology, relativity, and quantum field theory, especially ideas for cosmic acceleration, as well as contributions to undergraduate, graduate, and public science education".

Personal life

Carroll is married to Jennifer Ouellette, a science writer and the former Director of the Science & Entertainment Exchange.

Research

Carroll has worked on a number of topics in theoretical cosmology, field theory, and gravitation theory. His research papers include models of, and experimental constraints on, violations of Lorentz invariance; the appearance of closed timelike curves in general relativity; varieties of topological defects in field theory; and cosmological dynamics of extra spacetime dimensions. In recent years he has written extensively on models of dark energy and its interactions with ordinary matter and dark matter, as well as modifications of general relativity in cosmology.

Carroll has also worked on the arrow of time problem. He and Jennifer Chen posit that the Big Bang is not a unique occurrence as a result of all of the matter and energy in the universe originating in a singularity at the beginning of time, but rather one of many cosmic inflation events resulting from quantum fluctuations of vacuum energy in a cold De Sitter space. Carroll and Chen claim that the universe is infinitely old, but never reaches thermodynamic equilibrium as entropy increases continuously without limit due to the decreasing matter and energy density attributable to recurrent cosmic inflation. They assert that the universe is "statistically time-symmetric" insofar as it contains equal progressions of time "both forward and backward".

From Eternity To Here

From Eternity To Here: The Quest for the Ultimate Theory of Time is a popular cosmology book, by Carroll, published in January 2010. It tackles a fundamental open principle in physics: the arrow of time.

Atheism

Carroll is an outspoken atheist, who argues that scientific thinking leads one to a materialist worldview. He turned down an invitation to speak at a conference sponsored by the John Templeton Foundation, on the grounds that he did not want to appear to be supporting a reconciliation between science and religion. In 2004, he and Shadi Bartsch taught an undergraduate course at the University of Chicago on the history of atheism. In 2012 he organized the workshop "Moving Naturalism Forward", which brought together scientists and philosophers to discuss issues associated with a naturalistic worldview.

Publications

• Carroll, Sean (2003). Spacetime and Geometry: An Introduction to General Relativity. ISBN 0-8053-8732-3. 
• Carroll, Sean (2010). From Eternity To Here. ISBN 0-525-95133-4. 
• Carroll, Sean (2012). The Particle at the End of the Universe: How the Hunt for the Higgs Boson Leads Us to the Edge of a New World. ISBN 0-525-95359-0. 

External links

• Carroll's web site, Preposterous Universe
• Dark Matter, Dark Energy: The Dark Side of the Universe, lectures at The Teaching Company.
• Video of Sean Carroll's panel discussion, "Quantum to Cosmos," answering the biggest questions in physics today
• Video of Sean Carroll's lecture at the Quantum to Cosmos festival: "The Origin of the Universe and the Arrow of Time"
• Interview on The Colbert Report
• Carroll, Sean. "Higgs Boson with Sean Carroll". Sixty Symbols. Brady Haran for the University of Nottingham.