Spacetime emergence and cosmological dynamics in group field theory

About the Project

Many theories of quantum gravity agree that the spacetime geometry of Einstein’s general relativity needs to be replaced by a different underlying structure. In particular, spacetime may fundamentally consist of discrete “atoms”.

In this project you will study the group field theory approach to quantum gravity, which posits that spacetime is emergent from microscopic “atoms” of geometry, similar to how a fluid fundamentally consists of atoms and molecules. Simple models of cosmology can be derived from the collective behaviour of many such atoms and agree with what we expect for our Universe, while the Big Bang could be replaced by a “big bounce”. The goal of the project is to extend this past work by studying more realistic cosmologies including local inhomogeneities or gravitational waves; adding different types of matter and studying the role of matter as a “clock” in such theories; or constructing models of black holes in group field theory.

The project will mostly be based on analytical calculations but can include numerical work as well. Good prior knowledge of general relativity and quantum field theory at MSc level is essential, and at least a prior interest in quantum gravity would be desirable. The standard entry requirement for a PhD in mathematics at Sheffield is a first class BSc and a UK first-class or upper second class (2:1) MMath or MSc Merit (or international equivalent), in Mathematics or a related subject.

The Gravitation & Cosmology group at Sheffield consists of 6 academics, currently 12 PhD students and several postdoctoral researchers. We offer a friendly and active research environment with several weekly seminar and journal club events.

Funding Notes

This project is for Self-funded students or students with external funding.