On the field of definition of vector bundles on real varieties

We consider the possibility of defining over small fields the generators for theK-theory of strongly algebraic vector bundles on a real smooth variety. Furthermore we discuss how to construct in an explicit way algebraic models (defined over small fields and with other good arithmetic properties) of two-dimensional disconnected differential manifolds (and related singular spaces).Dedicated to the memory of C. BanicaThis work was partially sponsored by MURST and GNSAGA of CNR (Italy).