Gauge theory of gravity, lagrangian formalism on jet-gauge and jet-diffeomorphism groups: towards a unification with internal gauge interactions.

The geometrical formulation that describes the gauge interactions associated with internal symmetries is extended, with very little deviation from the standard viewpoint, to the case in which the symmetry group acts also on the space-time manifold. As a natural example we study the gravitational interaction recovering the Hilbert-Einstein theory. We also attempt to a simple, yet non trivial, mixing of gravity and electromagnetism (or more general internal interaction) by turning to gauge symmetry a central extension of the Poincaré group. The resulting Minimal Coupling Principle essentially ends up with the Einstein and Maxwell equations mixed by an electromagnetic current made of pure gravitational potentials. The equations of motion of a particle considering the mentioned mixing are also studied. On the other hand, the lagrangian theory of (internal) gauge interactions and gravity are reformulated in terms of jet-gauge groups and jet-diffeomorphism groups. In this scheme new fields, the gauge fields themselves, enter the theory playing a non-trivial role at the quantum level. In fact, they contribute to the mass of some of the intermediate vector bosons without damaging gauge symmetry.

 

Fecha: 
12/05/2004 - 14:00
Conferenciante: 
Eduardo Sánchez Sastre
Filiación: 
Instituto de Astrofísica de Andalucía - CSIC


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