Jul 5 – 10, 2021
Europe/Rome timezone

Semiclassics of Spin-Foams with Generic Causal Character

Jul 5, 2021, 5:00 PM
Talk in the parallel session Loop Quantum Gravity Loop Quantum Gravity


José Diogo Simão (Theoretical Physics Institute Jena)


The Lorentzian EPRL spin-foam model has been shown to asymptote in an appropriate regime to a Regge-like theory of gravity. Analogous results have recently been obtained for the Conrady-Hnybida (CH) extension of the model, but several questions regarding the amplitudes of time-like triangles remain open. In this talk I will present new progress on the asymptotic analysis of such amplitudes, in particular by proposing an alternative coherent-state parameterization of the theory and by generalizing to non-simplicial polyhedra. I will argue that, unlike for the other cases considered in the CH extension, the amplitude of time-like polygons is not exclusively dominated by Regge-like contributions. Finally I will discuss how the so-called "Cosine Problem" may naturally be avoided.

This talk reports on joint work with Sebastian Steinhaus, soon to be out on the Arxiv.

Primary authors

José Diogo Simão (Theoretical Physics Institute Jena) Dr Sebastian Steinhaus (Theoretical Physics institute Jena)

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