Some Friedmann cosmological solutions in the scale covariant theory of gravitation.
Space-times admitting a covariantly constant spinor field
Spinors on in supergravity
Stable bundles on hypercomplex surfaces
A hypercomplex manifold is a manifold equipped with three complex structures I, J, K satisfying the quaternionic relations. Let M be a 4-dimensional compact smooth manifold equipped with a hypercomplex structure, and E be a vector bundle on M. We show that the moduli space of anti-self-dual connections on E is also hypercomplex, and admits a strong HKT metric. We also study manifolds with (4,4)-supersymmetry, that is, Riemannian manifolds equipped with a pair of strong HKT-structures that have opposite...
Stable Minimal Surfaces and Spatial Topology in General Relativity.
Stationary states
Sui fondamenti dell’ottica relativistica
Il lavoro deduce, in ambito relativistico, le proprietà fondamentali di un flusso luminoso (congruenza nulla) mediante tecniche anolonome reali [2,3] e precisamente: caratteristiche geometrico-cinematiche del flusso (assolute e relative), teorema di Sachs [6] e proprietà dei nastri luminosi, con particolare riguardo ai parametri ottici e di deformazione, in spazi-tempo particolari (stazionarietà relativa, flussi geodetici, riferimenti trasportati per parallelismo dalla luce).
Superconnections: an interpretation of the standard model.
Sur les fibrés d'objets géométriques et leurs applications physiques
Symmetric space Cartan connections and gravity in three and four dimensions.
Synge-Beil and Riemann-Jacobi jet structures with applications to physics.