Tetrads is a package that implements computational representations and related operations for computing with tensors in a local system of references (the tetrad system). Many calculations in General Relativity can be dramatically simplified by defining an orthonormal tetrad and by expressing the metric and all other tensors in terms of this orthonormal tetrad.

Inert forms of these commands, representing the operations, having the same display and mathematical properties under differentiation, simplification etc., but holding the computations, consist of the same commands' names prefixed by the % character. The inert computations constructed with these commands can be activated when desired using the value command.

The e_ command represents the tetrad (also called vierbein)

You are very welcome to contribute ideas for improvements. There is a great deal of scope for changing and improving things; let us know your suggestions by writing to physics@maplesoft.com.

Landau, L.D., and Lifshitz, E.M. The Classical Theory of Fields, Course of Theoretical Physics Volume 2, fourth revised English edition. Elsevier, 1975.

Stephani, H., Kramer, D., MacCallum, M., Hoenselaers, C. Herlt, E. Exact Solutions of Einstein's Field Equations, Cambridge Monographs on Mathematical Physics, second edition. Cambridge University Press, 2003.

Compatibility

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The Overview of the Physics[Tetrads] Subpackage command was introduced in Maple 2015.

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