Seminar at CPHT

The particle physics group will be hosting a seminar by mathematical physicist Adrien Florio (Bielefeld U.) on Friday December 19th at 1pm in salle Louis Michel.

Thermalization and entanglement structures of relativistic fields: explorations in low-dimensions

Past decades have revealed the crucial role played by the entanglement structure of quantum states in explaining both phases of matter and thermalization—the emergence of statistical physics from unitary time evolution. Yet our understanding of entanglement in relativistic field theories remains limited, largely confined to conformal and holographic settings. At the same time, we don't have a clear picture of how our universe actually reached thermal equilibrium after inflation. We do not understand why the quark-gluon plasma produced in heavy-ion collisions thermalizes so fast, or what the actual phase diagram of QCD is. In this talk, I illustrate how progress can be made in filling this gap starting from the study of one-dimensional relativistic field theories. I present results on the real-time dynamics of the massive Schwinger model, which shares key features with QCD. In this setup, the medium created by hard back-to-back particles thermalizes through entanglement production. I then move on to discuss how a refined understanding of entanglement in relation to symmetries can serve as a practical tool for detecting and characterizing different phases of matter. Indeed, the so-called "entanglement asymmetry" related to the chiral symmetry in the Schwinger model can be computed analytically in the massless limit, as a function of temperature. Remarkably, it is parametrically more sensitive to symmetry breaking than the corresponding local order parameter, the chiral condensate.