HEP Theory Journal Club

KdV charges and Generalized Gibbs Ensemble in 2D CFT

Ioannis Tsiares

McGill

It is known that an isolated chaotic quantum system can exhibit thermal properties for a certain class of its observables. This is the content of the Eigenstate Thermalization Hypothesis (ETH), a conjecture which relates eigenstate expectation values with vevs in the usual Gibbs ensemble. There are also examples of quantum systems with more than one conserved charge (other than the Hamiltonian) that can still exhibit thermalization, this time though, in the Generalized Gibbs ensemble where one needs to take into account the extensive set of conserved quantities. CFTs in two spacetime dimensions are quantum theories that have an infinite dimensional algebra, the Virasoro algebra, and have an infinite set of conserved charges, the so-called KdV charges. Despite these facts, CFTs can still be chaotic so one would like to study ETH in this context. The purpose of this talk is to explore the structure of the Generalized Gibbs ensemble in a general 2D CFT and discuss the implications for ETH.