Evangelos S. Stamatis (1898–1990)

Review of some classical gravitational superenergy tensors using computational techniques

“…Collinson is a good pioneer of large calculations on the topic, but to validate his results we hope that others will obtain the same results using independent calculations. We also hope that any other program [7,8,14,18] will be able to do our calculations with an independent code and/or algorithms.…”

“…There are some problems with trusting programs which do automatic computations, especially when no exact coincidences arise when compared with older papers. All we can say is that our algorithm has been tested, besides in the present paper, on a large set of known Riemann properties (all those included in [11], among others) and calculations related to the Gauss-Bonnet invariant [14]. On the other hand, the fact that the implementation of the algorithm is part of a package, TTC (from now on we will use TTC to represent both the simplification algorithm and/or the package), allows us to test the results on explicit spacetimes.…”