Speaker
Description
We investigate the ultraviolet behavior of Lorentzian spinfoam quantum gravity by summing over 2-complexes, addressing the problem of infinite ambiguities relating to the triangulation dependence. We introduce spin-network stacks and their covariant extension, spinfoam stacks, which sum over families of 2-complexes generated by stacking faces onto root complexes. We demonstrate that the state sum exhibits an analog Bose-Einstein condensation phenomenon, where quantum geometry condenses to a dominant small spin configuration. In the large spin cut-off limit, the amplitudes localize to a topological theory. In this limit, the infinitely many ambiguities relating to triangulation dependence reduce to only finitely many degrees of freedom that are only associated to the boundary.
