SpinFrames: NP and GHP form of spinor equations

Authors: Thomas Bäckdahl and Steffen Aksteiner © 2015-2026 under GPL.

Introduction

SpinFrames is a package for Newman-Penrose (NP) and Geroch-Held-Penrose (GHP) expansions of covariant spinorial differential equations in dimension 4 of Lorentzian signature.

See SpinFrames.History

Download and installation

Current version: 0.5.6 (as of 23 December 2025). It is recommended to download the main xAct bundle, but you can also download the different files separately:

• SpinFrames.nb: source file.
• SpinFrames.m: package file. This file is automatically generated by Mathematica when SpinFrames.nb is saved. This is the only essential file.
• SpinFramesExamples.nb: examples file.
• General Public License.

See the file Installation notes.