Theoretical Physics

Princeton University, Princeton NJ

Investigators

Abstract

This award funds the research activities of Professors Igor Klebanov and Herman Verlinde at Princeton University. One of the deepest outstanding problems in fundamental physics is the merger of Einstein's theory of gravity with the known fact that the microscopic world is described by quantum mechanics. Einstein's theory predicts that the most compact possible objects are black holes, whose gravity is so strong that even light cannot escape; remarkably, such black holes appear to be abundantly present in the universe. Another salient prediction of Einstein's theory, gravitational waves (small "ripples" in the fabric of space-time), were observationally confirmed over the past year. However, a reconciliation between Einstein's theory of gravity and quantum mechanics has evaded a complete solution for many years. Recently it has been shown that certain quantum theories of gravity may be described by more conventional quantum-mechanical systems. This identification can teach us a great deal about the quantum behavior of black holes and about the evolution of the universe as a whole, thereby extending scientific knowledge at its most fundamental level. As a result, research in this area advances the national interest by promoting the progress of science in one of its most fundamental directions: the discovery and understanding of new physical laws. One of the goals of the research funded under this grant is to gain more thorough insight into the remarkable relation between Einstein's gravity and quantum-mechanical systems, and to use it to describe black holes and cosmology. Another goal is to better understand the behavior of matter when certain parameters such as the temperature and pressure are varied. This project also has an important educational and mentoring component which includes engaging students and postdocs in research and thereby preparing them for successful scientific careers. At a more technical level, this research will explore cutting-edge topics concerning gauge/gravity dualities, including their quantum-informational aspects and the emergence of an approximate locality in the gravitational description of quantum systems as well as the description of gravitational theories that contain fields of arbitrarily high intrinsic spin. A significant component of this research will explore quantum field theories which have conformal symmetry. Such theories describe certain second-order phase transitions. Via the gauge/gravity duality, conformal field theories are related to quantum gravity in negatively curved anti-de Sitter space. Conformal field theories in more than two dimensions will be studied using the methods of dimensional continuation and 1/N expansion. New information concerning quantum entanglement entropy in conformal field theories will be extracted. Studies of conformal field theory in two space-time dimensions and nearly-conformal quantum mechanics can teach us a great deal about low-dimensional models of quantum gravity and the properties of black holes.