2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/193786We perform a canonical quantization of gravity in a second-order formulation, taking as configuration variables those describing a 4-bein, not adapted to the space-time splitting. We outline how, neither if we fix the Lorentz frame before quantizing, nor if we perform no gauge fixing at all, is invariance under boost transformations affected by the quantization.8 pages, to appear in the proceedings of'' 4th Italian-Sino Workshop on Relativistic Astrophysics'', AIP Conference SeriesGeneral Relativity and Quantum Cosmologytext