Gravito-electromagnetic resonances in Minkowski space
  We consider the interaction between gravitational and electromagnetic
radiation propagating on a Minkowski background and look into the effects of
the former upon the latter. Not surprisingly, the coupling between these two
sources leads to gravitationally driven electromagnetic waves. At the second
perturbative level, the driving force appears as the superposition of two
waves, the properties of which are decided by the initial conditions. We find
that the Weyl-Maxwell interaction typically leads to electromagnetic beat-like
signals and, in some cases, to the resonant amplification of the driven
electromagnetic wave. For physically reasonable initial conditions, we show
that these resonances imply a linear (in time) growth for the amplitude of the
electromagnetic signal, with the overall amplification also depending on the
strength of the driving gravity wave. Finally, we provide order-of-magnitude
estimates of the achieved amplification by applying our analysis to
astrophysical environments where both gravitational and electromagnetic waves
are expected to coexist.
