Thermal spectra in QFTs and their reconstructions (Saso Grozdanov, Edimburgh)

Marzo 20, 2024@2:00 pm–3:30 pm
Aula 501

Seminario Fisica Teorica

The holographic duality provides an explicit reduction of quantum field theory (QFT) calculations in the semiclassical large-N limit to sets of “gravitational” differential equations whose analysis can reveal all details of the spectra of thermal QFT correlators. In the first part of my talk, I will discuss the state of affairs in our understanding of thermal spectra from the point of view of hydrodynamics, kinetic theory as well as perturbative QFTs and, finally, holographic QFTs. Then, I will discuss how, in spectra with analytic properties that appear in holography, a complete reconstruction of the spectrum and of the corresponding correlator is possible from only the knowledge of an infinite, discrete set of pole-skipping points (a “0/0” in the associated correlation function) traversed by a single (hydrodynamic) mode. The main step that will enable a unique reconstruction will be a series expansion of the problem in an inverse number of spacetime dimensions, expanded around infinity. Conceptually, this reduces the computation of a QFT correlator spectrum to performing a set of purely algebraic manipulations.

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