Enlarged geometries of gauge bundles

The geometrical picture of gauge theories must be enlarged when a gauge pot ential ceases to behave like a connection, as it does in electroweak intera ctions. When the gauge group has dimension four, the vector space isomorphi sm between spacetime and the gauge algebra is realized by a tetrad-like fie ld. The object measuring the deviation from a strict bundle structure has t he formal behavior of a spacetime connection, of which the deformed gauge f ield strength is the torsion. A generalized derivative emerges in terms of which the two Bianchi identities are formally recovered. Effects of gravita tional type turn up. The dynamical equations obtained correspond to a broke n gauge model on a curved spacetime.