On Frame-Invariance in Electrodynamics Giovanni Romanoa aDepartment of Structural Engineering, University of Naples Federico II, via Claudio 21, 80125 - Naples, Italy e-mail:
[email protected] Abstract The Faraday and Ampere` -Maxwell laws of electrodynamics in space- time manifold are formulated in terms of differential forms and exterior and Lie derivatives. Due to their natural behavior with respect to push-pull operations, these geometric objects are the suitable tools to deal with the space-time observer split of the events manifold and with frame-invariance properties. Frame-invariance is investigated in complete generality, referring to any automorphic transformation in space-time, in accord with the spirit of general relativity. A main result of the new geometric theory is the assess- ment of frame-invariance of space-time electromagnetic differential forms and induction laws and of their spatial counterparts under any change of frame. This target is reached by a suitable extension of the formula governing the correspondence between space-time and spatial differential forms in electro- dynamics to take relative motions in due account. The result modifies the statement made by Einstein in the 1905 paper on the relativity principle, and reproposed in the subsequent literature, and advocates the need for a revision of the theoretical framework of electrodynamics. Key words: Electrodynamics, frame-invariance, differential forms 1. Introduction arXiv:1209.5960v2 [physics.gen-ph] 10 Oct 2012 The history of electromagnetism is a really fascinating one, starting from the brilliant experimental discoveries by Romagnosi-Ørsted in 1800-1820 and by Zantedeschi-Henry-Faraday in 1829-30-31, and from the early beautiful theoretical abstractions that soon led to Faraday’s and Ampere` - Maxwell laws of electromagnetic inductions.