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November 21, 2013

Inflationary Cosmology

Inaugural Lecture Ponders Questions of the Universe

By Jocelyn Duffy

Is our universe truly unique? Or could our universe be just one of many universes - part of what cosmologists call a multiverse? Leading astrophysicist Alan H. Guth will address this question during the first Bennett-McWilliams Lecture.

Guth will speak at 4:30 p.m. on Tuesday, Dec. 3 in the Gates-Hillman Center's Rashid Auditorium. It is free and open to the public.  

The lecture is the first in a series funded by alumni Fred Bennett (S'86) and Bruce McWilliams (S'78, '78, '81), which will bring some of the leading scientists studying astrophysics and cosmology to Carnegie Mellon's Pittsburgh campus.

"We thank Fred Bennett and Bruce McWilliams for helping us to bring the world's leading cosmologists to Carnegie Mellon to interact with and inspire our faculty and students," Said Fred Gilman, dean of the Mellon College of Science.

Guth, the Victor F. Weisskopf Professor of Physics and a Margaret MacVicar Fellow at the Massachusetts Institute of Technology, was one of the inaugural recipients of the Fundamental Physics Prize from the Milner Foundation in 2012. The $3 million prize, an award amount that exceeds the Nobel Prize, is awarded for transformative advances in the field of physics.

In 1980, Guth proposed a modification to the standard big bang theory. His model of cosmic inflation involves an exponential expansion of the universe a tiny fraction of a second after the big bang..   Inflation explained why the universe is homogeneous and looks the same in all directions at large distance scales. Quantum fluctuations in density are the seeds for structure and get magnified to cosmic size with the universe's expansion to the present day.

Over the years, Guth's theory has been rigorously tested and refined, and is now widely accepted by physicists. Cosmologists have been able to detect the radiation left over from the big bang. This radiation, called cosmic microwave background radiation (CMB), has patterns that match what is predicted by Guth's inflation theory.

In his lecture, Guth will explain how inflation works and how it can account for the properties seen in the CMB. He will also talk about how inflation could produce more than one universe or even a multiverse containing a number of "pocket universes."

Guth has also received the Franklin Medal for Physics from the Franklin Institute, the Dirac Prize from the International Center for Theoretical Physics, the Cosmology Prize of the Peter Gruber Foundation, and the Newton Prize of the U.K.'s Institute of Physics. He is a member of the National Academy of Sciences and the American Academy of Arts and Sciences.