Lemaitre-Tolman-Bondi dust solutions in f(R) gravity
  We derive a class of non-static inhomogeneous dust solutions in f(R) gravity
described by the Lemaitre-Tolman-Bondi (LTB) metric. The field equations are
fully integrated for all parameter subcases and compared with analogous
subcases of LTB dust solutions of GR. Since the solutions do not admit regular
symmetry centres, we have two possibilities: (i) a spherical dust cloud with
angle deficit acting as the source of a vacuum Schwarzschild-like solution
associated with a global monopole, or (ii) fully regular dust wormholes without
angle deficit, whose rest frames are homeomorphic to the Schwarzschild-Kruskal
manifold or to a 3d torus. The compatibility between the LTB metric and generic
f(R) ansatzes furnishes an "inverse procedure" to generate LTB solutions whose
sources are found from the f(R) geometry. While the resulting fluids may have
an elusive physical interpretation, they can be used as exact non--perturbative
toy models in theoretical and cosmological applications of f(R) theories.
