The two-point correlation function is calculated in the Lorentzian Engle-Pereira-Rovelli-Livine spinfoam model and shown to match with the one in Regge calculus in a proper limit: large boundary spins j→ and small Barbero-Immirzi parameter γ→0, keeping the size of the quantum geometry A∼γj finite and fixed. Compared to the Euclidean case, the definition of a Lorentzian boundary state involves a new feature: the notion of past- and future-pointing intertwiners. The semiclassical correlation function is obtained for a time-oriented semiclassical boundary state.
|Original language||English (US)|
|Journal||Physical Review D - Particles, Fields, Gravitation and Cosmology|
|State||Published - Nov 16 2012|
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
- Physics and Astronomy (miscellaneous)