Powered by Indico
v3.2.9
The observables we are used to talk about to describe the physics at accessible high energies, such as correlation functions, S-matrix or even the wavefunction of the universe in cosmology are boundary quantities: they are just functions of the in and out data, with all the time evolution connected them which is integrated out. However, in a putative full-fledge theory of quantum gravity the boundary observables are the only ones which are guaranteed to be well-defined. While in asymptotically AdS space-times the correlators are known to define CFTs directly on the boundary, with the actual gauge/gravity duality establishing a weak-strong correspondence, it is unclear whether and, in case, which class of theories are attached to the boundary of asymptotically flat and cosmological space-times. In this talk, we will argue how novel combinatorial structures underlie observables -- no matter if they are in asymptotically AdS, flat or cosmological space-times -- and how they offer first principle formulations of the theory directly on the boundary without any need to refer to a bulk.