FAU^2 Workshop on quantum gravity across scales: from physics at the Planck scale to effective theories

Session

Session 4

21 May 2025, 16:50

ECAP Laboratory Building

58. Berry phases and von Neumann algebras for wormholes in AdS/CFT

Johanna Erdmenger

21/05/2025, 16:50

invited talk

Within the AdS/CFT correspondence, two manifestations of the black hole information paradox are given by the non-isometric nature of the bulk-boundary map and by the factorisation puzzle. By considering time-shifted microstates of the eternal black hole, we demonstrate that both these puzzles may be simultaneously resolved by taking into account non-local quantum corrections that correspond to...

42. Lorentzian cosmological path integrals from effective spin foams

Sebastian Steinhaus

21/05/2025, 17:30

invited talk

In this talk, I will present a spatially flat Lorentzian cosmological subsector of (effective) spin foams and show first steps towards computing its path integral and a continuous time limit.
I will begin by introducing the classical theory in Lorentzian Regge calculus, where we discuss the classical discrete equations of motion and their solutions, coupling (massless) scalar fields,...

48. Extracting effective continuum physics from quantum gravity

Daniele Oriti (Dept Fisica Teorica, Universidad Complutense de Madrid)

21/05/2025, 18:10

invited talk

We outline key steps, assumptions and approximations taken to extract an effective continuum dynamics for both cosmological backgrounds and perturbations around them (thus effective quantum field theory) from quantum gravity models in the tensorial group field theory (thus spin foam and LQG) formalism. We also discuss in more detail recent results, showing an emergent cosmological acceleration...

44. Emergent early and late acceleration from Quantum Gravity

Dr Luca Marchetti (Okinawa Institute of Science and Technology)

21/05/2025, 18:50

contributed talk

Recent cosmological observations are increasingly challenging the standard understanding of the physics underlying cosmic acceleration. In this talk, I present a new mechanism for acceleration, emerging from quantum gravity interactions as described by Group Field Theory (GFT) models. For a broad class of physically motivated GFT interactions, the resulting cosmological dynamics exhibit a...