Inner Structure of Black Holes in Eddington-inspired Born-Infeld
  gravity: the role of mass inflation
  We investigate the interior dynamics of accreting black holes in
Eddington-inspired Born-Infeld gravity using the homogeneous approximation and
taking charge as a surrogate for angular momentum, showing that accretion can
have an enormous impact on their inner structure. We find that, unlike in
general relativity, there is a minimum accretion rate bellow which the mass
inflation instability, which drives the centre-of-mass streaming density to
exponentially high values in an extremely short interval of time, does not
occur. We further show that, above this threshold, mass inflation takes place
inside black holes very much in the same way as in general relativity, but is
brought to a halt at a maximum energy density which is, in general, much
smaller than the fundamental energy density of the theory. We conjecture that
some of these results may be a common feature of modified gravity theories in
which significant deviations from general relativity manifest themselves at
very high densities.
