Decoherence and coherence in gravitational, electric and strong nuclear fields

Inspired in the work of Erich Joos which appreciated the role played by matter in making the decoherence of the gravitational field, we developed an alternative way of treating the former problem. Besides this, we used the alternative approach to examine the decoherence of the electric field performed by the conduction electrons in metals. As a counterpoint, we studied the coherence of the electric color field inside nucleons, which renders the strong field a totally quantum character.