GRTensorIII is a Maple package for component calculations in General Relativity. It is now available for free download from https://gitlab.com/grtensor/grtensor/wikis/home. It provides a number of useful features:
– interactive entry of spacetime metrics (including basis and NP formats)
– large number of standard tensor definitions (curvature tensors, vector field expansion/shear, scalar invariants)
– a powerful mechanism to define new tensor objects (grdef) without programming
– commands to simplify and extract component values
GRTensorIII is provided as a standard Maple package. It has been tested with Maple 2015 and 2016.
GRTensorIII is an update of the package GRTensorII developed by Peter Musgrave, Denis Pollney and Kayll Lake in the 1990s. GRTensorII has continued to be used by relativists and this update brings the package in line with “modern” Maple versions and fixes some platform-specific issues on MacOS. Most of the original code has been retained, with changes to allow it be released as a Maple module in a single package.
Peter Musgrave would like to thank Maple Software for the donation of Maple licenses. Thanks also to Eric Poisson for beta testing.