riem SciMax Toolbox rinvariant

SciMax Toolbox >> riemann

riemann

Maxima Function

Calling Sequence

riemann (dis)

Description

A function in the ctensor (component tensor) package. riemann computes the Riemann curvature tensor from the given metric and the corresponding Christoffel symbols. The following index conventions are used:

l      _l       _l       _l   _m    _l   _m
R[i,j,k,l] =  R    = |      - |      + |    |   - |    |
ijk     ij,k     ik,j     mk   ij    mj   ik

This notation is consistent with the notation used by the itensor package and its icurvature function. If the optional argument dis is true, the non-zero components riem[i,j,k,l] will be displayed. As with the Einstein tensor, various switches set by the user control the simplification of the components of the Riemann tensor. If ratriemann is true, then rational simplification will be done. If ratfac is true then each of the components will also be factored.

If the variable cframe_flag is false, the Riemann tensor is computed directly from the Christoffel-symbols. If cframe_flag is true, the covariant Riemann-tensor is computed first from the frame field coefficients.

riem SciMax Toolbox rinvariant