Andrea Puhm - Towards flat space holography via diamonds on the celestial sphere

Tuesday 16 Nov 2021, 14:00 → 16:00 Europe/Zurich

4/3-006 - TH Conference Room (CERN)

Abstract:

The basic observable of quantum gravity in asymptotically flat spacetimes is the S-matrix. When recast in a basis of boost eigenstates scattering amplitudes transform as conformal correlators of primary operators in the dual ''celestial CFT''. This observation together with novel insights about the infrared aspects of gauge theory and gravity have reinvigorated attempts at a holographic principle for flat space. Essential to building a holographic dictionary is to understand the spectrum and the symmetries of the dual theory. I will describe recent progress in this direction. A natural language for describing the (conformally) soft sector of scattering is via celestial diamonds which encode the structure of global conformal multiplets and, upon adding supersymmetry, stack into a pyramid. They unify the discussion of QFT soft theorems, (asymptotic) symmetry generators and Goldstone modes appearing in conformal dressings. Combining these ingredients I will end with some speculations on effective descriptions for the conformally soft sector of celestial CFT which captures the spontaneous (asymptotic) symmetry breaking dynamics.