**Ruth
Britto**

**Associate
Professor in Theoretical Physics**

Dublin 2

Ireland

+353 1 896 3945

**Current
Teaching**

MA22S3 Fourier Analysis for Science, Michaelmas 2017

**Research**

Scattering amplitudes play a key role in high-energy physics. Not only do they describe the actual scattering taking place in collider experiments--of current importance in the era of the Large Hadron Collider (LHC)--but they also illuminate the formal aspects of quantum field theories, such as divergent behavior or integrability. Amplitudes are thus useful both practically and formally, but their availability is limited by the difficulty of computing them.

As
the number of particles in the scattering process increases, or the
perturbative expansion is carried out to higher order, the
traditional technique of Feynman rules fails to be feasibly
implementable. This difficulty has prompted the innovation of new
techniques. Notable among these are *on-shell*
techniques,
in which the basic building blocks are complete amplitudes, rather
than fundamental interactions. The on-shell framework has surpassed
traditional Feynman diagram expansions, both in delivering new
results and in expressing them in formulas that are not only compact,
but also deeply illuminating. My research develops the on-shell
framework to incorporate all theories and configurations of physical
interest, building upon recent developments in pure mathematics.

**ERC Consolidator
Grant Project: Loop
Amplitudes in Quantum Field Theory [****CutLoops****]**

The European Research Council has awarded funding to work on computing multiloop amplitudes from their discontinuities, by examining the relations between generalized cuts and the Hopf algebra of multiple polylogarithms and then exploiting them to produce methods for calculation.

There is an opening for a PhD student to begin in 2018. For information on how to apply, click here.

For further information, contact loop-amplitudes@maths.tcd.ie.

**Publications**

Full list of publications on INSPIRE

Lecture notes: Constructing scattering amplitudes

Review article: Loop amplitudes in gauge theories: modern analytic approaches