String-like degrees of freedom in strongly coupled QFTs

Tuesday 18 Jun 2024, 12:00 → 14:00 Europe/Rome

Aula Conversi (Dip. di Fisica - Edificio G. Marconi)

SEMINARIO CHIAMATA DIRETTA

Quantum field theories at strong coupling exhibit a number of phenomena that are not immediately visible to perturbation theory. A surprising feature is that, beside point particles, the spectrum of strongly-coupled QFTs can include two-dimensional, string-like excitations. A famous example of this are the QCD strings which appear to play a role in the confining phase of the strong nuclear force. While a microscopic description of QCD strings is currently out of reach, I will discuss an approach to study similar classes of objects in the context of supersymmetric quantum field theories. In this setting, string theory provides a natural framework for studying the string-like excitations, which are realized by wrapping membranes in an internal space. This gives rise to a rich interplay between the geometric properties of the internal space, the mathematical theory of modular forms, and the properties of the strings. Building on this interplay, I will discuss how it is sometime possible to obtain an exact description of the strings, from which one can in turn extract detailed information about the spectrum and physical properties of the QFT.