Séminaire de Physique Théorique
Unraveling complexity: out-of-equilibrium dynamics and holographyGiuseppe Di Giulio
Thursday 20 March 2025 14:00 - Salle des séminaires - Salle 1180, bâtiment E2
Résumé :
Recently, quantum information theory has brought profound insights into quantum gravity through the AdS/CFT correspondence. A major role in this program is played by complexity measures, which quantify how difficult it is to construct a given quantum state. Indeed, complexity is expected to probe dynamical spacetimes in time regimes where other quantum information measures, such as entanglement entropy, are not insightful. In this talk, I will present some results on different approaches to complexity in out-of-equilibrium quantum field theories (QFTs). First, I will discuss the evolution of the subsystem complexity after a global quench in a free scalar 1+1-dimensional QFT. In the second part of the talk, I will focus on the spread complexity, which roughly quantifies the size of the space of states visited along quantum dynamics. I will discuss the spread complexity after a local quench in generic conformal field theories. In both the cases analyzed, the complexity dynamics are compared with the holographic complexity proposals in the corresponding gravity duals, finding qualitative and quantitative agreement.
Liens :