Resonances in space-time provide for over-unity devices which extract their energy from the fabric (torsion,curvature) of space-time itself. The theory and engineering principles in this paper seem to me to be DIRECTLY APPLICABLE to understanding the TPU and designing a working device. Skip over the differential geometry mathematics and look at the graphs and pictures, and read the explanations.
http://www.aias.us/documents/miscellaneous/Spacetime-Dev.pdf (http://www.aias.us/documents/miscellaneous/Spacetime-Dev.pdf)
I hope you find it as useful as I do.