Lattice Quantum Field Theory

The interest of our research group lies in the investigation of nonperturbative aspects of quantum field theories, mainly using numerical methods such as Monte Carlo methods. We are particularly interested in the properties of Quantum Chromodynamics (QCD) which is an integral part of the Standard Model (SM) of particle physics describing the fundamental forces between all known elementary particles. QCD defines the theory of the strong interactions between quarks and gluons governing the nuclear forces and the inner structure of hadrons, such as, for example, the proton, the neutron or the pion. QCD can be simulated as a quantum field theory on a four-dimensional hypercubic space-time lattice using high-performance supercomputers.

Changing the lattice resolution towards the continuum limit.

Recently, we have become interested in applying convolutional neural networks and machine learning techniques to Lattice Quantum Field Theories. This opens up a completely new way to simulate QCD with quantum or classically perfect discretizations of space-time such that results can be obtained directly in the continuum.

Convolutional neural network for lattice QCD.

Our group is a member of the Extended Twisted Mass Collaboration (ETMC) which constitutes a worldwide effort to combine theoretical and computational expertise in order to perform large-scale high-precision lattice-QCD calculations in realistic settings. Our current main research interest is the calculation of the hadronic contributions to the anomalous magnetic moment of the muon, which is also the focus of other research groups at the ITP.

We are also involved in the Flavour Lattice Averaging Group (FLAG). Within this collaboration we review lattice-QCD results related to low-energy physics of the SM with the aim of making them easily accessible to the particle physics community and to provide them with a single source of reliable information on lattice results. FLAG has become the widely accepted standard authority for lattice-QCD results.