Bounds on the Polymer Scale from Gamma Ray Bursts

Alejandro García-Chung (ICN-UNAM/UAM-I)

RESUMEN: Within Loop Quantum Gravity, the polymer representation has been suggested as a possible matter field quantization scheme. Here we apply a version of the polymer quantization to the electromagnetic field, in a reduced phase space setting, and derive the corresponding effective (i.e., semiclassical) Hamiltonian. In this limit the theory is nonlinear, deviating significantly from standard electromagnetism. In particular, we study the propagation of an electromagnetic pulse and compare our theoretical results with Gamma Ray Burst observations. This comparison reveals that the polymer scale must be 35 orders of magnitude below the quantum gravity scale, casting doubts on the viability of this quantization.