PD

• PD is the ordinary derivative operator chosen as fiducial origin for the affice space of derivatives.

• PD can be understood as the "partial derivative" operator.
• It acts on all manifolds but it does not see abstract indices.
• It is an ordinary derivative operator because it has no curvature and no torsion. Apart from that it is fully unspecified.
• SortCovDs[expr,PD] sorts all PD derivatives with covariant abstract indices.
• See: Section 4.5.
• See also: DefCovD.
• New in version 0.
• Last update: 16-X-2007 for version 0.9.3 of xTensor`.

Created by Mathematica  (May 16, 2008)