2009/02/10 by Valentino Lacquaniti, VALENTINO LACQUANITI, Giovanni Montani +1
Physics and Astronomy · #Black Holes and Theoretical Physics #Quantum Mechanics and Non-Hermitian Physics #Quantum and Classical Electrodynamics #gr-qc
paper · pdf · doi:10.1142/s0218271809014844
published as Int.J.Mod.Phys.D18:929-946,2009 · 21 pages, to appear on IJMPD
arxiv created 2009/02/10 · openalex publication_date 2009/06/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
A long-standing problem in Kaluza–Klein models is the description of matter dynamics. Within the 5D model, the dimensional reduction of the geodesic motion for a 5D free test particle formally restores electrodynamics, but the reduced 4D particle shows a charge–mass ratio that is upper-bounded, such that it cannot fit in with any kind of elementary particle. At the same time, from the quantum dynamics viewpoint, there is the problem of the generation of huge massive modes. We present a criticism against the 5D geodesic approach and face the hypothesis that in Kaluza–Klein space the geodesic motion does not deal with the real dynamics of the test particle. We propose a new approach: starting from the conservation equation for the 5D matter tensor, within the Papapetrou multipole expansion, we prove that the 5D dynamical equation differs from the 5D geodesic one. Our new equation provides right coupling terms without bounding and in such a scheme the tower of massive modes is removed.