Inspired by classical work of Bel and Robinson, a natural purely algebraic
construction of super-energy (s-e) tensors for arbitrary fields is presente
d, having good mathematical and physical properties.
Remarkably, there appear quantities with mathematical characteristics of en
ergy densities satisfying the dominant property, which provides s-e estimat
es useful for global results and helpful in other matters.
For physical fields, higher order (super)(n)-energy tensors involving the f
ield and its derivatives arise. In special relativity, they provide infinit
ely many conserved quantities.
The interchange of s-e between different fields is shown. The discontinuity
propagation law in Einstein-Maxwell fields is related to s-e tensors, prov
iding quantities conserved along null hypersurfaces. Finally, conserved s-e
currents are found for any minimally coupled scalar field whenever there i
s a Killing vector.