The large Q expansion in CFT

July 9, 2019
11:30am to 1:00pm

Room 218

General Public
Christian Copetti

Room 218


The theme will have to do with CFT and the simplifications that occur by considering operators of large (global) charge Q acting on the vacuum. These (effectively) put the system at finite energy and charge density.

Here is a list of papers that may be useful:

"On the CFT Operator Spectrum at Large Global Charge" (Hellerman, Orlando, Reffert, Watanabe)

"Conformal Bootstrap At Large Charge" (Jafferis, Mukhametzhanov, Zhiboedov)

"Semiclassics, Goldstone Bosons and CFT data" (Rattazzi, Monin, Seibold, Pirtskhalava)

The basic idea is similar to the large c bootstrap of Kaplan and Fitzpatrick, but it has application out of holography since having global charges is more constrictive.

We will show that many universal features may be captured by semi-classical expansion around a bosonic Goldstone theory. Also commenting on the uniqueness of such description (under some assumptions) by solving the bootstrap equations. This leaves an interesting open question, since systems of finite charge and energy include excitations of a Fermi surface (i.e. Landau Fermi liquid theory) which however does not seem to appear as a solution.

This talk will not be about holography, so I encourage people interested in CFT in general to attend!