Tilted Lema\^itre model and the dark flow
  In the last years, the peculiar velocities of many X-ray galaxies clusters
with respect to the distance have been measured directly in the rest frame of
the cosmic microwave background radiation (CBR), using the kinematic
Sunyaev-Zeldovich (kSZ) effect. These measures prove that exists a highly
coherent motion, extending out to at least to ~1 Gpc, of the matter rest frame
with respect to the CBR rest frame. This global motion was named "dark flow".
By using an inhomogeneous spherically symmetric "tilted" Lema\^itre model, we
could explain the dark flow if we assume a linear increase with distance of the
peculiar velocities, which is in principle allowed by these observations. This
linear increase of the dark flow with the distance has the same behavior that
the intrinsic dipole, due to the kinematic acceleration, which appears in the
Hubble law of the Lema\^itre model. In the "tilted" Lema\^itre model
considered, we consider that the radiation orthogonal congruence is a perfect
fluid and the matter "tilted" congruence is an imperfect fluid with heat flux.
