Finite-time future singularities in modified gravity
  We review finite-time future singularities in modified gravity. We
reconstruct an explicit model of modified gravity realizing a crossing of the
phantom divide and show that the Big Rip singularity appears in the modified
gravitational theory. It is also demonstrated that the (finite-time) Big Rip
singularity in the modified gravity is transformed into the infinite-time
singularity in the corresponding scalar field theory obtained through the
conformal transformation. Furthermore, we study several models of modified
gravity which produce accelerating cosmologies ending at the finite-time future
singularities of all four known types.
