The Theoretical Physics Group has a long and distinguished history as one of the world’s leading centres for theoretical physics. Our work covers a wide range of research areas bound together by the theme of fundamental questions in cosmology, gravity, particle physics, and quantum theory. Read an overview of our research interests on the Theory Group Poster (PDF).
Research topics and staff
Our research broadly divides into three key areas, with substantial overlap and interaction between each stream.
Research topics and staff
Cosmology, Gravity and Quantum Field Theory
Since its foundation, the Group has played a central role in developing theories of particle physics and cosmology, in conjunction with exploring the fundamental structure of gravitational theories. The unprecedented growth in the quality and quantity of observational data and the stunning observation of Gravitational Waves (GWs) make this a particularly exciting time. Our research seeks innovative ways of testing particle physics and quantum gravity theories against hard astrophysical data, such as Cosmic Microwave Background data, GWs and supernovae results, to lead the development of the underlying theoretical models.
- Carlo Contaldi: Physics of the very early universe, inflation and structure formation, cosmic microwave background (CMB), gravitational waves, statistics and inference in observational cosmology.
- Joao Magueijo: Classical and quantum cosmology, with a long-standing interest in “varying constant’’ theories and, more recently, in the cosmological constant problem.
- Arttu Rajantie: Dynamics of quantum fields in the early Universe, during and after inflation, study of magnetic monopoles and their production mechanisms.
- Claudia de Rham: Developing and testing new paradigms to address some of the fundamental open questions at the interface between gravity, quantum field theory and cosmology.
- Andrew Tolley: Effective field theories, interplay of quantum field theory and gravity, quantum gravity, early-universe and string cosmology, inflationary theories and their alternatives, modified and massive gravity, gravitational waves, and Galileon theories among other topics.
String Theory and M-Theory
The Group’s research effort in string/M-theory is one of the largest and strongest in the world. String/M-theory is a proposed quantum framework for unifying the Standard Model of Particle Physics with General Relativity. The theory also provides deep insights into the non-perturbative structure of quantum field theory through the AdS/CFT correspondence. Fundamentally our research aims to understand the physical and mathematical structure of the theory and to explore its symmetries, while elucidating connections between string theory and geometry, the nature of black holes, integrability and supersymmetric field theories, among other topics.
- Michael Duff: Unified theories of the elementary particles, quantum gravity, supergravity, Kaluza-Klein theory, superstrings, supermembranes, M-theory and quantum information theory.
- Jerome Gauntlett: String theory, quantum field theory and black holes as well as the associated geometric structures that arise.
- Amihay Hanany: Aspects of branes and supersymmetric gauge theories in string theory, with strong connections to geometric singularities, using various techniques in quantum field theory.
- Chris Hull: String theory and M-theory, in particular on its mathematical and geometric aspects, applications to gravity and gauge theory and the role of supersymmetry and duality symmetry.
- Kellogg Stelle: Currently focussed on studies of effective field theories on supergravity brane solutions and the implications of gravitational higher derivative quantum corrections, particularly for black holes and for the early universe.
- Arkady Tseytlin: String theory in curved backgrounds, aspects of gauge theory, string theory dualities and integrability
- Daniel Waldram: String theory and M-theory, quantum field theory and gravity, with particular interest in the connections with geometry.
- Toby Wiseman: Focussed on understanding black holes and gravity in a variety of exotic settings, such as in the context of string theory, extra dimensions, modified theories of gravity and the AdS-CFT correspondence.
Quantum Foundations, Quantum Gravity and Complexity
The Group also works on other approaches to quantum gravity including causal set theory, which posits that spacetime is fundamentally discrete. A further key focus is the study of the foundations of quantum mechanics, be it via the path integral approach or decoherent histories, and aspects of time in quantum mechanics. Finally, we have a strong interest in complex systems, both in conventional condensed matter systems and more generally in the analysis of networks.
- Fay Dowker: The causal set approach to the problem of quantum gravity in which spacetime is postulated to be fundamentally discrete and to take the form of a discrete partial order; the foundations of quantum mechanics, concentrating on developing the path integral approach.
- Tim Evans: The behaviour of many-body systems both in and out of equilibrium and particularly complex systems, especially those described by networks, addressing both theoretical questions and applications.
- Jonathan Halliwell: Foundations of quantum theory, the decoherent histories approach to quantum theory, emergent classicality, aspects of time in quantum mechanics and especially Leggett-Garg inequality tests of macrorealism (the temporal analogues of Bell inequality tests).
- Hugh Jones: Applications of PT symmetry in quantum mechanics, quantum field theory and classical optics.
- Ray Rivers: Phase transitions in quantum field theory of condensed matter systems; superconductors, cold Fermi gases; defects; complex systems and social network analysis; maximum entropy and stochastic cost-benefit analysis of archaeological data.