Approaches to Quantum Gravity

Questions and answers 337of some sort of scattering process, thus the corresponding transition amplitude)will require the calculation only to a finite order in perturbation theory.This means obtaining only approximate answers, but it may well be goodenough for all practical purposes (again, this is the case in ordinary QFT). Inorder for this possibility to be realized, of course, one needs to clarify furtherthe physical interpretation of the GFT coupling constant, beyond what isalready known. Last, the infinite sums appear in the perturbative expansion ofthe full, microscopic, partition function; it is possible that, after more work,and with a deeper understanding of the GFT formalism, one will be able toobtain effective theories adapted to a more macroscopic context, e.g. suitableto study some specific phase of the theory (like the “condensed” one correspondingto a continuum approximation of spacetime), from the microscopicGFT; if this is the case the infinite sums of the perturbative expansion ofthe microscopic GFT will not be directly relevant for answering questions inthis phase/approximation, and these questions may instead require only finitecalculations in the effective theory.