Modern theoretical particle physics describes nature through the language of quantum field theory (QFT.) Over the decades since QFT was first developed, physicists have been amazed at the range of phenomena QFT can describe - from boiling water to quantum gravity - as well as the subtlety of the description (for example, string theory in a certain spacetime is believed to be equivalent to an ordinary QFT which lives on the boundary of the string theoretic spacetime.) QFT has even become important in pure mathematics. But there is a great deal that is mysterious and the particle theory group in Edinburgh is at work at the frontiers of our understanding of the subject.

## Scattering Amplitudes

Quantum field theories and quantum mechanical generalisations of the field theories familiar to James Clerk Maxwell, based on lines of force which exist even in the vacuum. Because they are quantum mechnical, predictions in QFT represent probablities that certain phenomena occur. Scattering amplitudes encode the probabilities for certain scattering phenomena to occur, for example the probability that two electrons will scatter at a certain angle or that two gluons create a Higgs boson at the LHC. The study of scattering amplitudes has risen in prominence recently, spurred by the LHC, and has lead to some magnificent progress in our understanding of the quantum mechanical structure of field theory. One remarkable fact about scattering amplitudes is that, in a certain precise sense, scattering of fundamental particle in gauge theories "squares" into the scattering of gravitons, the quanta of the gravitational field. This is an example of the unity of physics: research motivated by the LHC has revealed new QFT magic in gravity. The group in Edinburgh studies amplitudes from a variety of points of view: we perform detailed calculations for the LHC, we develop new tools to sum up important effects which occur at different orders of the perturbative expansion of scattering amplitudes, as well as studying the connection between gauge theory and gravity.

## Applications of Quantum Field Theory

We are interested in applications of statistical field theory methods to the turbulence problem. This includes both theoretical analytic work as well as high-resolution numerical simulations of the Navier-Stokes equation. We are also interested in the conseqences of turbulence in the Universe to the evolution of cosmic magnetic fields.

## Physics Beyond the Standard Model

The Standard Model of particle physics has been extraordinarily successful at predicting the results of a host of experiments since it was first written down in the 1970s. But there are plenty of reasons for thinking that the Standard Model is an incomplete description of nature. Among the glaring problems are the fact that the Standard Model contains a large number of very peculiar numbers (such as the Higgs boson mass) and issues with gravity. But also the Standard Model does not explain the observed dark matter or the origin of mass. Our group is interested in theories which extend the Standard Model at energies we can explore at the LHC and which also address the problem of baryogenesis - why is there so much more matter than antimatter in the universe?

## PhD project opportunities in Fundamental Theory

## People in Fundamental Theory

Telephone numbers in the list below are shown as UK numbers. Callers from outside the UK should remove the leading zero and use the UK country code (+44).

Name | Position | Contact details | Location | Photo |
---|---|---|---|---|

Academic staff | ||||

Richard Ball | Professor | r.d.ball [at] ed.ac.uk | JCMB 4420 | |

Arjun Berera | Professor | ab [at] ph.ed.ac.uk | JCMB 4412 | |

Luigi Del Debbio | Professor | luigi.del.debbio [at] ed.ac.uk | JCMB 4418 | |

Einan Gardi | Director of Higgs Centre for Theoretical Physics | einan.gardi [at] ed.ac.uk | JCMB 4416 | |

Donal O'Connell | Reader | donal [at] staffmail.ed.ac.uk | JCMB 4405 | |

Jenni Smillie | Royal Society Research Fellow | j.m.smillie [at] ed.ac.uk | JCMB 4411 | |

Roman Zwicky | Reader | roman.zwicky [at] ed.ac.uk | JCMB 4415 |