2007/05/23 by Friedrich W. Hehl, Yu. N. Obukhov, Yuri N. Obukhov · 2 citations
Physics and Astronomy · #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Noncommutative and Quantum Gravity Theories #gr-qc #hep-th #physics.class-ph
paper · pdf · doi:10.1007/s10714-007-0601-5
published as Gen.Rel.Grav.40:1239-1248,2008 · 13 pages latex
arxiv created 2007/05/23 · openalex publication_date 2008/01/08 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The coupling of the electromagnetic field to gravity is discussed. In the premetric axiomatic approach based on the experimentally well established conservation laws of electric charge and magnetic flux, the Maxwell equations are the same irrespective of the presence or absence of gravity. In this sense, one can say that the charge "substratum" and the flux "substratum" are not influenced by the gravitational field directly. However, the interrelation between these fundamental substrata, formalized as the \it spacetime relation H=H(F) between the 2-forms of the electromagnetic excitation H and the electromagnetic field strength F, is affected by gravity. Thus the validity of the equivalence principle for electromagnetism depends on the form of the spacetime relation. We discuss the nonlocal and local linear constitutive relations and demonstrate that the spacetime metric can be accompanied also by skewon, dilaton, and axion fields. All these premetric companions of the metric may eventually lead to a violation of the equivalence principle.