Theoretical Particle Physics at City, University of London

Particle physics is at a critical juncture. The LHC experiments have found the last missing element of the Standard Model: the Higgs boson, and placed stringent restrictions on possible new physics. At the same time, in the theoretical physics community there are outstanding problems in our understanding of quantum gauge and gravity theories, which undoubtedly would benefit from new observations at the LHC and other experiments. This project will investigate two key problems in modern theoretical physics.

Firstly, we will examine strongly coupled gauge theories using the so-called gauge/string correspondence. Much remains to be learnt about strongly coupled gauge theories. There have been significant breakthroughs in understanding certain gauge theories using the gauge/string correspondence.

In particular, our group has been at the forefront of developing mathematical methods known as integrability which provide us with a powerful tool with which to investigate strongly-interacting gauge theories with little supersymmetry as well as precision test holography. Our group has also been pioneering Lattice Field Theory methods for strings in holographic backgrounds.

LFT is particularly effective, because the low-dimensionality of the string worldsheet (1+1d) and the anti-commuting scalar nature of Green-Schwarz fermions significantly reduce the processor power needed, while being applicable in a many physically-important holographic backgrounds. Low-supersymmetry gauge theories have also have intimate links to the mathematics of algebraic geometry and algebraic number theory that can be identified using Machine Learning methods.

In this project we will significantly build on these results to exploit these new mathematical tools and methods to understand the strong-coupling dynamics of less supersymmetric gauge theories and their gauge/string dualities.

Secondly, we will explore beyond-the-Standard-Model physics that can be obtained as a consistent low-energy theory from string theory. String theory has provided a framework for unifying gauge and gravity interactions into a single consistent quantum theory. One of the key challenges has been to identify particular examples of string theory compactifications which will lead to realistic low-energy physics.

This has remained a major challenge since conventional algorithms have very long run-times. Our group has pioneered the use of novel Machine Learning methods to obtain high-precision, detailed information about stringy phenomenology models. We have also been at the forefront of precision analytic computation of non-perturbative effects that play a key role in string phenomenology.

In this project we will exploit these developments to systematically chart the String Theory Landscape. The remarkable speed of the new methods means that we can explore physical properties of string models that were completely out of reach with conventional algorithms. Additionally, because of our strong links with Data and Computer Science experts, we are in a unique position to exploit the synergies that will arise in this multi-disciplinary Theoretical Physics-focused collaboration and their potential impact on a much wider set of applications.

The combined expertise of our group, our track-record and our international and UK collaborators, places us in an ideal position to achieve the goals set-out above.