Over the last 10 years, our understanding of the Universe has advanced tremendously thanks to powerful theory and observations. We now know how old our Universe is, and how much matter and energy there is in the Universe, quite accurately. However, the more we learn about the Universe, the more challenges we seem to face: recent observations clearly indicate that we do not understand 95 percent of energy/ matter in the Universe today! How about the history of the Universe? How much do we know about the Universe when it was very young—perhaps as young as a tiny fraction of a second old? Powerful development in theory and observations of cosmology has finally made it possible to peer into the epoch before the Big Bang—the period called Cosmic Inflation. How can we possibly "see" such an early epoch? It is often said that we are living in the Golden Age of Cosmology, but at the same time we are living in an extraordinarily challenging moment for Cosmology. What is the nature of Dark Matter and Dark Energy? What powered the Big Bang? In this lecture I will review the outstanding questions and recent developments—Frontiers in Cosmology.


Eiichiro Komatsu, Associate Professor in Astronomy at the University of Texas at Austin, is the Director of the newly formed Texas Cosmology Center. Dr. Komatsu obtained his Ph.D. in astronomy from Tohoku University, Japan, in 2001 for work done at Princeton University from 1999- 2001. He is primarily a theoretical cosmologist, but uses both theoretical and observational means to tackle various questions about the Universe such as its history, evolution, structure, and composition. He is a member of the science team for NASA's Wilkinson Microwave Anisotropy Probe (WMAP) satellite mission. WMAP's recent measurements of anisotropy in the Cosmic Microwave Background Radiation, the afterglow of the Big Bang, have advanced our knowledge of the Universe tremendously; Science magazine called them the "Breakthrough of the Year" in 2003. Komatsu's contributions have been recognized internationally with several awards, including the Astronomical Society of Japan's Young Astronomer Award (2004), an Alfred P. Sloan Research Fellowship (2005), and, most recently, the International Union of Pure and Applied Physics Young Physicist's Prize (2008). He is currently working with his colleagues at The University of Texas at Austin Department of Astronomy on developing the Hobby-Eberly Telescope Dark Energy Experiment, which will shed new light on Dark Energy.


The Great Lectures in Astronomy series features distinguished speakers presenting a topic in modern astronomy for interested non-astronomers. The lectures are sponsored by the The University of Texas at Austin McDonald Observatory and Department of Astronomy Board of Visitors.