BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Renate Loll DTSTART:20210217T170000Z DTEND:20210217T183000Z DTSTAMP:20260423T040933Z UID:QG-AA/5 DESCRIPTION:Title: Ob servables for Quantum Gravity: Going Nonperturbative\nby Renate Loll a s part of Quantum Gravity Across Approaches\n\n\nAbstract\nThe physical na ture and explicit construction of observables in quantum gravity depend on length scale and context\, and tend to be very different in perturbative and nonperturbative regimes. My talk will focus on the latter\, which is c haracterised by the absence of a pre-existing background and where spaceti me is not described by a smooth metric tensor. What constitutes appropriat e (pre-)gravitational observables near the Planck scale is not known a pri ori\, and their operational definition depends on how diffeomorphism symme try is implemented nonperturbatively. Natural candidates are "quantum gene ralisations" of nonlocal classical observables\, which in general will nee d to be renormalized and may display unexpected\, anomalous behaviour. To compare with classical results\, one also needs some control on how to coa rse-grain. The construction and implementation of nonperturbative quantum observables poses creative and technical challenges that can be addressed successfully in sufficiently complete candidate theories\, as I will illus trate in the context of Causal Dynamical Triangulations.\n LOCATION:https://researchseminars.org/talk/QG-AA/5/ END:VEVENT END:VCALENDAR