Abstract We propose a general model where quintessence couples to electromagnetism via its kinetic term. This novelty generalizes the linear dependence of gauge function on ϕ , commonly adopted in literature. The interaction naturally induces time variation fine-structure constant that can be formulated within disformally coupled framework, akin Gordon metric. Through suitable parametrization s...

Recently, an intriguing relationship (the double copy ) has been discovered between theories like electromagnetism and gravity. This potentially gives us a new way to think about gravity, there are also practical applications involving the efficient calculation of gravitational observables how simulate gravity using optical systems. In this tutorial, we will review what is known copy, argue tha...

Standard formulae of classical electromagnetism for the forces between electric charges in motion derived from retarded potentials are compared with those obtained from a recently developed relativistic classical electrodynamic theory with an instantaneous inter-charge force. Problems discussed include small angle Ruther-ford scattering, Jackson's recent 'torque paradox' and circular Keplerian ...