References & Citations
General Relativity and Quantum Cosmology
Title: Partial absence of cosine problem in 3d Lorentzian spin foams
(Submitted on 25 Apr 2024)
Abstract: We study the semi-classical limit of the recently proposed coherent spin foam model for (2+1) Lorentzian quantum gravity. Specifically, we analyze the gluing equations derived from the stationary phase approximation of the vertex amplitude. Typically these exhibit two solutions yielding a cosine of the Regge action. However, by inspection of the algebraic equations as well as their geometrical realization, we show in this note that the behavior is more nuanced: when all triangles are either spacelike or timelike, two solutions exist. In any other case, only a single solution is obtained, thus yielding a single Regge exponential.
Submission history
From: Alexander Florian Jercher [view email][v1] Thu, 25 Apr 2024 18:00:19 GMT (543kb,D)
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