RUI: Amplitudes in Gauge theory and Gravity

Bowdoin College, Brunswick ME

Investigators

Abstract

This award funds the research activities of Professor Stephen Naculich at Bowdoin College. The research of Professor Naculich is part of an on-going effort by the worldwide community of theoretical elementary particle physicists to develop mathematical models to explain the nature and behavior of the smallest constituents of matter (the so-called "elementary particles"). More specifically, this research aims at developing more efficient mathematical tools for calculating the predictions of a certain class of existing theories known as "gauge theories", and extending these methods to more general theories. A second goal of this research is to explore links between gauge theories on the one hand, and theories that describe the behavior of gravitons, the particles responsible for the force of gravity, on the other. The insights gained through this research will be disseminated through journal publications, seminars, and conference proceedings. As a result, this research will advance the national interest by promoting the progress of science in one of its most fundamental directions: the discovery and understanding of new physical law. This project is also expected to have significant broader impacts, since it integrally involves participation by undergraduate students. It therefore will contribute to their education by providing hands-on training in research methods in theoretical physics, as well as exposure to diverse topics such as quantum mechanics, group theory, and quantum field theory. Such involvement will encourage and prepare highly-talented students for graduate study and careers in critical scientific fields. In more technical terms, this project will focus on the structure of perturbative scattering amplitudes in gauge theories and gravity and the relations between them. In particular, the research will involve continued exploration of the recently discovered "color-factor symmetry" of gauge-theory amplitudes, particularly at loop level, its extension to more general theories, and its relationship to color-kinematic duality. This project will further investigate Cachazo-He-Yuan representations for gauge-theory and gravity amplitudes involving massive particles, and also loop-level amplitudes, with particular focus on infrared divergences. This research will extend the study of the classification of operators in effective field theories contributing to subleading and subsubleading soft theorems. Finally, this project will continue to explore the Regge limit of gravitational scattering amplitudes, focusing on the interplay with infrared divergences and soft theorems, and the relationship with analogous issues in gauge theory.