The Berkeley Center for Theoretical Physics was created to address many of the fundamental questions of the new century involving matter and spacetime. The Center aims to attract the very top young researchers in the field, as faculty, postdoctoral fellows and visiting scholars, to create an exciting environment fostering creative new ideas. Experts on particle physics, cosmology and string theory, traditional strengths of Berkeley, will be housed together in a single new Center.
Particles and their interactions are governed by symmetries; sometimes by symmetries with imperfections. The defects in the symmetries are crucial, leading to some particles being heavy and some light, some interactions being strong and others weak, and to much else besides. What new force causes these imperfections in the symmetry? This force is quite unlike the known gravitational, electromagnetic, strong and weak forces, and the present theoretical challenge to understand it will soon be resolved by experiments in the United States and Europe. The new force may involve a new field filling all space — as if the whole universe was bathed in something like a magnetic field — or it may herald a new understanding of space and time. An earlier revolution in our understanding of space and time was Einstein's 1905 Theory of Relativity, with unfamiliar notions leading to profound consequences, for example for nuclear energy and antimatter. As we draw towards the centenary of this discovery, perhaps in our own time we will discover supermatter or excitations of matter proclaiming the existence of extra dimensions of space quite unlike the large ones so familiar to us.
It is commonly believed that these familiar dimensions of space became large during an early era of the universe when length scales underwent a period of exponential inflation. What is the physical theory underlying such catastrophic early cosmic behaviour, and how can it be tested? From studies of the gravitational behaviour of the universe as a whole, we have learnt some remarkable results: most of the matter in the universe does not shine and is dark, and there is a field energy pervading all space causing the universe to expand at an ever faster rate. What are the mysterious dark matter and dark energy, which dominate the universe, but are so unlike the particles and fields that we measure in the lab on Earth?
String Theory and Quantum Gravity
The physics of particles and the physics of the universe must be one. The quantum realm and the geometric spacetime realm of gravity must be reconciled. The reconciliation, which eluded Bohr and Einstein, can now be glimpsed in string theory. Despite considerable progress of the last two decades, string theory remains in its infancy. How do the familiar electron and photon emerge as the low energy limits of the oscillation of the string? How could the theory have produced an era of cosmic inflation, followed by our more gentle times of a calmer expanding universe? What keys are needed to unlock the potential of the theory, allowing calculations of particle masses and force strengths? What new unexpected phenomena might it predict to be lurking near at hand?
- Superstring Theory
- Field Theory (coming soon)