Quantum Field Theory


Quantum Field Theory (QFT) is an overarching framework in theoretical physics. It describes quantum systems with degrees of freedom at every point in space, that interact with each other locally. Its applications range from statistical and condensed matter physics, to particle physics, cosmology and quantum gravity.

QFT is extremely successful in providing precise predictions when the interactions can be treated as a small perturbation. However, in the complementary case of strong coupling, while QFT often gives the correct qualitative explanation of the observed phenomena, it lacks a systematic approach to compute observables from first principles. Relatedly, we do not have yet a general understanding of QFT that covers both weak and strong coupling regimes, and encompasses all the possible observables, ranging from scattering amplitude, to correlation functions of local operators, to those of extended operators. Finding better ways to compute will likely also lead to a better understanding of what QFT really is. 

Head of Research Group
Lorenzo Di Pietro


Last update: 09-30-2022 - 18:50