The interply among the magnetism and gravitative fields ought to be vital in physics as a result of the magnetism force and gravity area unit 2 types of basic forces in nature

The interply among the magnetism and gravitative fields ought to be vital
in physics as a result of the magnetism force and gravity area unit 2 types of
basic forces in nature. Within the Lagrangian of the equality Einstein-Maxwell
theory, solely the quadratic term of Maxwell tensor is said on to magnetism and
gravitative fields, which may even be looked because the interaction between
Maxwell field and therefore the spacetime metric tensor. However, the interactions between magnetism field and curvature tensor aren’t enclosed during this
magnetism theory. Drummond et al.1 found that such quite the couplings may
well be appeared naturally in QED with the gauge boson effective action originating from one-loop vacuum polarization on a sinusoidal background spacetime. During this effective theory, all of the coupling constant area unit terribly
tiny and their values area unit of the order of the square of the Arthur Compton
wavelength of the lepton ? since the coupling between the magnetism field and
curvature tensor is simply a quantum development during this case. However,
the models with arbitrary coupling constant are investigated wide in refs.2-8
for a few physical motivation.