Online – Holografia Celestial

Celestial Holography is a proposal for the application of the holographic principle to asymptotically flat spacetimes based on the observation that the ${\cal S}$-matrix in a conformal primary basis behaves as a conformal correlator in a two-dimensional conformal field theory living on the celestial sphere at null infinity. The proposal emerged from the realization that soft theorems imply symmetries of the ${\cal S}$-matrix. In this introductory course we are going to explain basic aspects of this holographic correspondence. We discuss the symmetries of asymptotically flat spacetimes and show that soft graviton theorems imply that they are also symmetries of the quantum gravity ${\cal S}$-matrix. In particular we show that superrotation symmetry implies that the ${\cal S}$-matrix obeys a two-dimensional stress tensor Ward identity after transforming to a conformal primary basis. After introducing such bases and defining celestial amplitudes we discuss some of its consequences. In particular, we derive the celestial OPE and discuss the associated holographic symmetry algebras.

Pré-requisitos

• quantum field theory,  general relativity

Professor

• Leonardo de Gioia