The extrinsic method
A mathematical method for physical applications

© Thierry PERIAT : Texts, photos, and ideas

The extrinsic method

is a mathematical method. It is a helpful tool to get answers to the so-called (E) question. The (E) question is: “Consider a deformed tensor product (DTP) in E(D, K) where usually K represents either R or C. Consider the image of that DTP in the dual E*(D, K) of E(D, K). How can I divide it and get a pair ([P], z) in M(D, K) x E(D, K)?”

Please discover the basics and the method on the page “Mathematical methods”.

Applications (personal propositions)

In physics, I have applied this method in two domains:

-           The geodesic deviation equation for weak gravitational fields; (text coming soon again here).

-           The Heisenberg’s uncertainty principle; on this website: “A. Einstein versus W. Heisenberg” and on the www.researchgate.net website.

Applications (in the literature)

In the community, I newly discovered an article (under the Common Creative licence) titled:

-           Quantum effective action for degenerate vector field theory“ published on the 17th October 2018 by the American Physical Society in Phys. Rev. D 98, 085014 (2018)” in which the formula (5) has exactly the formalism induced by the analysis of the Lorentz force density (alias Lorentz-Einstein force in my semantic) with the extrinsic method when the geometry is invariant (see more details in my document ISBN… 031-1 directly on the www.researchgate.net website).

F = - G-1. H

Where G represents the local non-degenerated four-dimensional metric and H a quasi-classical Hessian of which the interpretation is related to an EM potential.

Provisory conclusion

My hope is to have been able to convince the readers that that method can have some advantages in physics.

© Thierry PERIAT, 23 November 2018.