Artigo
Loop quantization of a model for D = 1 + 2 (anti)de sitter gravity coupled to topological matter
Autor
Oporto, Zui
Constantinidis, Clisthenis P.
Piguet, Olivier
Institución
Resumen
We present a complete quantization of Lorentzian D = 1 + 2 gravity with cosmological constant, coupled to a set of topological matter fields. The approach of loop quantum gravity is used thanks to a partial gauge fixing leaving a residual gauge invariance under a compact semi-simple gauge group, namely Spin(4) = SU(2) × SU(2). A pair of quantum observables is con-
structed, which are non-trivial despite being gauge-equivalent to zero at the classical level. A semi-classical approximation based on appropriately defined coherent states shows non-vanishing expectation values for them, thus not reproducing their classical behaviour.