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Germeshausen Professor and Department Head, Program in Science, Technology & Society, MIT
Senior Lecturer, Department of Physics
PHONE: (617) 253-4062
ASSISTANT: Randyn Miller (617) 253-3452
Area of Physics:
My physics research is in particle cosmology, working at the interface of particle physics and gravitation. In particular, most of my work has focused on inflationary cosmology, an early phase during which the size of the universe expanded exponentially quickly just fractions of a second after the big bang. (For a review, see "Inflationary Cosmology.") Since 2011, I have been leading a research group at MIT with Alan Guth on aspects of cosmic inflation. Much like the early universe, our group has grown rapidly.
My interest has centered on whether successful inflation might be achieved with familiar particles from the Standard Model of particle physics, such as the Higgs boson. Recent work has focused on predictions from models with several interacting fields, and whether multifield models produce new features that could be observed in the cosmic microwave background radiation, compared to single-field models. Much of this work has also concerned interactions between matter and gravity that extend beyond Einstein's general relativity, and whether such "nonminimal couplings" might account for specific observable features in the spectrum of primordial perturbations. For a brief and accessible introduction to this work, see "Elegant Wiggles: Why the Universe is Lumpy."
I have also studied how such inflationary expansion might have come to an end in a process called "reheating," when the energy that had driven the rapid expansion was converted into particles more like the kind we see around us today. In many models, the decay of this inflationary energy occurs resonantly (somewhat akin to a laser, rather than an ordinary light bulb), far from equilibrium. In some cases these resonant interactions can amplify large gravitational fluctuations, which might (in principle) prove detectable in the cosmic microwave background radiation. Moreover, the techniques used to study the dynamics of reheating can also be applied to many other kinds of interactions, such as phase transitions in condensed-matter physics and in nuclear physics. For my work on reheating and gravitational fluctuations, I have collaborated with Bruce Bassett and Roy Maartens.
Another topic of interest is the behavior of gravity in models in which our universe has more than four dimensions. Higher-dimensional theories have many motivations, such as superstring theories. Interesting questions arise when one tries to understand cosmological consequences -- such as the expansion rate of the universe or the strength of gravity over various distance scales -- of these higher-dimensional models. For this work I have collaborated with Alan Guth, Philip Mannheim, and Ali Nayeri. (For a review, see "Inflationary Cosmology.")
A complementary line of inquiry focuses on the complex dynamics of networks, with applications to understanding the growth and development of scientific research fields: a cross between statistical mechanics and the history and sociology of science. Together with Luis Bettencourt, I have been exploring whether the critical dynamics of topological phase transitions in scientists' collaboration networks might betray signs of universality. Research areas in fields as disparate as theoretical physics and biomedicine might undergo the same basic teamwork and co-authorship mechanisms early in their histories, even though they involve vastly different numbers of researchers and published articles per year.
David Kaiser is Germeshausen Professor of the History of Science and Department Head of MIT's Program in Science, Technology, and Society, and a Senior Lecturer in MIT's Department of Physics. He completed an A.B. in physics at Dartmouth College and Ph.D.s in physics and the history of science at Harvard University. Kaiser's historical research focuses on the development of physics in the United States during the Cold War, looking at how the discipline has evolved at the intersection of politics, culture, and the changing shape of higher education. His physics research focuses on early-universe cosmology, working at the interface of particle physics and gravitation.
Kaiser is author of the award-winning book, Drawing Theories Apart: The Dispersion of Feynman Diagrams in Postwar Physics (University of Chicago Press, 2005), which traces how Richard Feynman's idiosyncratic approach to quantum physics entered the mainstream. His latest book, How the Hippies Saved Physics: Science, Counterculture, and the Quantum Revival (W. W. Norton, 2011), charts the early history of Bell's theorem and quantum entanglement and was named "Book of the Year" by Physics World magazine. His edited volumes include Pedagogy and the Practice of Science: Historical and Contemporary Perspectives (MIT Press, 2005), and Becoming MIT: Moments of Decision (MIT Press, 2010). He is presently working on two books about gravity: a physics textbook on gravitation and cosmology co-authored with Alan Guth; and a historical study of Einstein's general relativity over the course of the twentieth century. He is also completing a book entitled American Physics and the Cold War Bubble (University of Chicago Press, in preparation). Kaiser serves as an editor of the journal, Historical Studies in the Natural Sciences.
Kaiser's work has been featured in such venues as Nature, Science, and Scientific American; the New York Times, Harper's, the Huffington Post, and the London Review of Books; and onNational Public Radio, BBC Radio, and NOVA television programs. In 2010, he was elected a Fellow of the American Physical Society. Other honors include awards for best book in the field from the History of Science Society (2007) and the Forum for the History of Science in America (2006); the Harold E. Edgerton Faculty Achievement Award for distinguished tenure-track faculty member at MIT (2006); and the Leroy Apker Award for best undergraduate physics student from the American Physical Society (1993). In 2012 Kaiser was named a MacVicar Faculty Fellow, MIT's highest honor for excellence in undergraduate teaching. That same year, he also received the Frank E. Perkins Award for excellence in mentoring graduate students.
A list of publications are located here.
Last updated on March 5, 2015 10:52 AM