Area bounds and gauge fixing: Alternative canonical variables for loop gravity
Phys. Rev. D 114, 026018 – Published 14 July, 2026
DOI: https://doi.org/10.1103/bd3d-5r9t
Abstract
We use a canonical parametrization of twisted geometries describing the classical phase space of loop quantum gravity on a fixed graph, and establish its explicit correspondence with the associated frame bases and spinorial descriptions. Applied to the two-vertex model, this framework yields analytical bounds on the evolution of the total area, proving the existence of a nonvanishing lower bound at finite times. These findings, previously observed only numerically, suggest a bouncelike behavior and highlight the usefulness of these variables for the study of more general configurations. As a second result, the canonical variables are shown to simplify the gauge-fixing procedure, generalizing previous results restricted to two-vertex models with four links.