Working on the leading edge of high-energy theoretical particle physics for more than thirty years, Renata Kallosh has been a professor of physics at Stanford University since 1990. She has done much of the important research in the still-evolving field of supersymmetry and black holes. In particular, she was the first to perform quantization of supergravity. Using string theory in her investigations of puzzling questions about quantum gravity, Dr. Kallosh has provided a formula for the macroscopic entropy of a sub-class of extreme black holes and shown it to be universal. Her current studies also involve looking at the possible role of M-theory in cosmology. With her husband, Andrei Linde, she examined some of the assumptions in recent cosmic models, which were built on the discovery that the expansion of the universe appears to be speeding up, and found that dark energy, the mysterious component of space thought to drive acceleration, may eventually become negative, which may lead to a collapse of the universe. More recently she was working on general issues of string cosmology where a significant progress has been achieved due to a new mechanism of stabilization of the runaway moduli, which she discovered in collaboration with Shamit Kachru, Andrei Linde, and Sandip Trivedi. Dr. Kallosh is a native of Russia and earned her baccalaureate degree at Moscow State University. After taking her Ph.D. in physics at Moscow's Lebedev Physical Institute in 1968, she remained there as a junior fellow and was named a professor in 1981. Nine years later, she became a scientific associate at CERN for a year before immigrating to the United States and joining the Stanford faculty. Dr. Kallosh was one of the organizers of the Nobel Symposium on “String Theory and Cosmology” that was held last year in Stockholm. A member of the editorial board of the Journal of High Energy Physics, she has published some 175 papers on particle physics, supergravity, string theory and cosmology.