Dérivations, formes et opérateurs usuels sur les champs spinoriels des variétés différentiables de dimension paire
We shall show that no reductive splitting of the spin group exists in dimension other than in dimension . In dimension there are reductive splittings in any signature. Euclidean and Lorentzian signatures are reviewed in particular and signature is investigated explicitly in detail. Reductive splittings allow to define a global -connection over spacetime which encodes in an weird way the holonomy of the standard spin connection. The standard Barbero-Immirzi (BI) connection used in LQG is...