The proceedings of the 1998 Spanish relativity meeting in honour of Lluís Bel contain several topics which Bel and his collaborators have worked on, namely the superenergy tensor and frames of reference. There are also many communications on cosmology, mathematical relativity and gravitational collapse.

The proceedings of the 1998 Spanish relativity meeting in honour of Lluís Bel contain several topics which Bel and his collaborators have worked on, namely the superenergy tensor and frames of reference. There are also many communications on cosmology, mathematical relativity and gravitational collapse.