GRTensorIII for Maple has been released Announcement on Hyperspace@GU Additional Information: GRTensorIII is a Maple package for component calculations in General Relativity. It is now available for free download from gitlab 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. Peter Musgrave Denis Pollney Kayll Lake The following are interim updates to GRTensorII which allows it to run in Windows 32 and 64 bit modes and on Macs under Maple 2016. Until we get to fix the sqrt issue use the following after restart in your worksheet kernelopts(unread = `sqrt'): Mac users can find installation instructions below: GRTensor II is a computer algebra package for performing calculations in the general area of differential geometry. Its purpose is the calculation of tensor components on curved spacetimes specified in terms of a metric or set of basis vectors. The package contains a library of standard definitions of a large number of commonly used curvature tensors, as well as the Newman-Penrose formalism. The standard object libraries are easily expandable by a facility for defining new tensors. Calculations can be carried out in spaces of arbitrary dimension, and in multiple spacetimes simultaneously. Though originally designed for use in the field of general relativity, GRTensorII is useful in many other fields. GRTensor II is not a stand alone package, but requires an algebraic engine. The program was originally developed for MapleV. GRTensorII runs with all versions of Maple,
Maple V Release 3 to Maple 11.
A limited version (GRTensorM) has been ported to
Mathematica.GRTensor II and related software and documentation are distributed free of charge as an aide for both research and teaching. |

On the web since 1994. GRTensor has been in public distribution since 1992. Visit the GRTensorII site at The Albert-Einstein-Institut (AEI), in Golm near Potsdam. |