Research in High Energy Physics:
Task C: Theoretical High Energy Physics

W. Taylor (PI),

Center for Theoretical Physics, Laboratory for Nuclear Science
Massachusetts Institute of Technology

Project Summary

The MIT High Energy Theory Group proposes a broad research program in theoretical high energy physics. The proposed research ranges from dark energy, cosmology, quantum gravity, and string theory at the highest energy scales to questions in particle physics phenomenology and field theory at lower energies and includes research that connects with quantum information theory. The proposed grant would help support the research of seven principal investigators —Alan Guth, Daniel Harlow, Hong Liu, Tracy Slatyer, Washington Taylor, Jesse Thaler, and Barton Zwiebach — as well as a number of graduate students and postdocs.

Objectives of the proposed research program cover almost all fields of current research in high energy physics. The proposal includes investigations of quantum and classical gravity, incorporating research on the rapidly developing connections between quantum gravity and quantum information theory, which are relevant for understanding black holes, cosmology, and the fundamental nature of gravity theories, as well as foundational aspects of string theory and work towards characterizing the variety of string and supergravity vacua, and their connections to observable physics.  Work on quantum field theory (QFT) includes more theoretical aspects related to foundations of QFT, developing new effective descriptions of non-equilibrium processes in condensed matter physics, nuclear physics, and astrophysics, and QFT in the context of the standard model and its possible extensions. For phenomenology and beyond-the-standard- model physics, this proposal is aimed at understanding how to extract hints of new physics from new data from colliders and astrophysical observations, and combining QFT and machine learning techniques for measurements in quantum chromodynamics. Parts of the proposal focus in particular on questions about how to identify and characterize dark matter, which may have already given rise to astrophysical signatures, including modeling and testing signatures of dark matter physics in astrophysical and cosmological datasets. Dark energy presumably indicates a nonzero vacuum energy density, and explaining the small value of this constant is a key challenge for fundamental physics. The proposal includes work on eternal inflation, which is one approach of resolving this issue, as well as more concrete phenomenological questions about cosmology and inflation.

The proposed work will make use of a variety of physics techniques, including perturbative and non- perturbative methods in quantum field theory. Computational methods will play a significant role not only in understanding phenomenological data from the LHC and other experiments, but also in systematically analyzing string theory solutions and in understanding connections between quantum information systems and gravity theories. Recent developments in mathematics, particularly geometry, also play an important role in parts of the project related to quantum gravity and string theory. The use of many of these methods involves interactions and collaboration with other faculty at MIT and elsewhere in the physics, math, and computer science departments.

The direct impact of this research will be an improved understanding of the nature of fundamental forces, quantum systems, and the large-scale structure of our universe, leading to a deeper understanding of the theoretical structure describing physical phenomena. Indirect impacts include the development of physical, mathematical, and computational tools with broad applicability, and the training of students and postdocs in theoretical physics.