Problems in Theoretical Physics

University Of California-Santa Barbara, Santa Barbara CA

Investigators

Abstract

This award funds the research activities of Professors Joseph Polchinski and Robert Sugar at the University of California, Santa Barbara (UCSB). The research of these two professors is in the field of high energy physics. The long-term objectives of this field are to identify the basic building blocks of matter and to determine the interactions among them that give rise to the physical world we observe. Great progress has been made towards these objectives through the development of the so-called Standard Model of high energy physics, which provides fundamental descriptions of three of the four interactions of nature: the strong, electromagnetic and weak. What is missing is a fundamental theory of gravity, and the unification of gravity with the other interactions. The objective of Polchinski's work under this grant is to create these missing elements. Sugar's research, by contrast, is aimed at making very precise calculations which, when combined with equally precise experiments, will provide rigorous tests of the Standard Model and possibly point to breakdowns of this model that will require the development of new physical ideas. Thus, research under this award advances the national interest by promoting the progress of science in one of its most fundamental directions. In addition to contributing to a deeper understanding of the fundamental laws of physics, this project is also expected to have significant broader impacts. The education of graduate students and postdoctoral fellows is a major activity of the grant. Moreover, part of the effort associated with Professor Sugar's research is aimed at developing large-scale computational infrastructure for the entire U.S. community of physicists working in related areas. The approach being taken has broad possibilities for application to computationally-intensive problems in many areas of science and engineering. More technically, research in quantum gravity will focus on the dynamics of strings and branes, especially near the black hole horizon. The role of brane dynamics in string compactification will also be made precise. A wide range of questions in quantum field theory and holography will be studied, focusing on basic principles. Research in lattice gauge theory will be directed at the generation of gauge configurations for multiple applications, the properties of the light pseudoscalar mesons and B mesons, and the anomalous magnetic moment of the muon.