2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/215634We apply the Lieb-Robinson bounds technique to find the maximum speed of interaction in a spin model with topological order whose low-energy effective theory describes light [see X.-G. Wen, \prb {\bf 68}, 115413 (2003)]. The maximum speed of interactions is found in two dimensions is bounded from above less than $\sqrt{2} e$ times the speed of emerging light, giving a strong indication that light is indeed the maximum speed of interactions. This result does not rely on mean field theoretic methods. In higher spatial dimensions, the Lieb-Robinson speed is conjectured to increase linearly with the dimension itself. Implications for the horizon problem in cosmology are discussed.4 pages, 1 eps figure. Bound improvedQuantum PhysicsStrongly Correlated ElectronsGeneral Relativity and Quantum CosmologyHigh Energy Physics - Latticetext