The gravitational field’s energy and momentum definitions are treated in extensive gravitation theories, through the generalization of the energymomentum pseudotensor, defined by Einstein in general relativity. This ...

We construct a realization Ap of A in the spaces Lp(Rd;Cm), 1 p < 1, that generates a contractive strongly continuous semigroup. First, by using form methods, we obtain generation of holomorphic semigroups when the ...

This research thesis is mainly devoted to the study of noncoercive Dirich let problems with discontinuous coefficients in unbounded domains. The presence of the noncoercive operator does not allow us to use classical the ...