  Recent surveys have been reporting bulk peculiar flows considerably faster
than expected. Bulk flows are moving matter and matter in motion implies
nonzero energy flux. In relativity, as opposed to Newtonian physics, matter
fluxes gravitate as well, since they also contribute to the energy-momentum
tensor. The gravitational input of the "peculiar" flux survives at the linear
level and it can drastically change our understanding of the way bulk flows
have evolved in time. By default, the Newtonian analysis of peculiar motions
bypasses the relativistic flux-contribution to the gravitational field. The
problem is that there are also studies, with an otherwise relativistic profile,
which inadvertently do the same. As result, these treatments reduce to
Newtonian and they misleadingly reproduce the slow Newtonian growth-rate of
linear peculiar velocities. In contrast, by accounting for the flux effects,
the proper relativistic analysis arrives at a considerably stronger growth. We
show that it is the flux input of the moving matter to gravity that separates
the relativistic studies of peculiar motions from the rest and, in so doing, it
could provide an answer to the bulk-flow question.
