# Systems related to Tensor Calculus

# Classi

Classi is a set of classification programs for geometries in general
relativity written for SHEEP. The most important classification program
is the program for invariant classification of geometries. For theory of
this classification see [1,2], , for an examplified description of the
implemented algorithm including the facility for complex numbers in module
`hlpfns`

and `funtst`

see [3]. Some results obtained using this classification
program are found in [4,5,6,7,8].

classi is available by anonymous ftp from euclid.maths.qmw.ac.uk
Classi is available by anonymous ftp from euclid.maths.qmw.ac.uk

## References (incomplete list)

- A. Karlhede, Gen. Rel. Grav. 12 (1980) 693.
- A. Karlhede, Gen. Rel. Grav. 12 (1981) 963.
- J.E. Aman and A. Karlhede, "An Algorithmic Classification of
Geometries in General Relativity". Proceedings of the 1981 ACM
Symposium on Symbolic and Algebraic Computation (Symsac '81) (1981) 79.
- J.E. Aman and A. Karlhede "A Computer-Aided Complete Classification of
Geometries in General Relativity. First Results",
Phys. Lett. 80A (1980) 229.
- A. Karlhede and J.E. Aman "Classifying Geometries in General Relativity",
Abstracts of contributed papers, 9th International Conference on General
Relativity and Gravitation (1980) 104.
- A. Karlhede and J.E. Aman "A Classification of the Vacuum D Metrics",
Preprint, University of Stockholm (1981).
- A. Karlhede and J.E. Aman "Inequivalent Metrics with Equal Spin
Coefficients", Gen. Rel. Grav. (1981).
- A. Karlhede, U. Lindstrom and J.E. Aman, "A Note on a Local Effect at
the Schwarzschild Sphere", in Gen. Rel. Grav. 14 (1982) 569.

Special Purpose Systems

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Last updated: December 19, 1994