  We present constraints on the cosmic growth history with recent cosmological
data, allowing for deviations from Lambda CDM as might arise if cosmic
acceleration is due to modifications to GR or inhomogeneous dark energy. We
combine measures of the cosmic expansion history, from Type 1a supernovae,
baryon acoustic oscillations and the CMB, with constraints on the growth of
structure from recent galaxy, CMB and weak lensing surveys along with
ISW-galaxy cross-correlations. Deviations from Lambda CDM are parameterized by
phenomenological modifications to the Poisson equation and the relationship
between the two Newtonian potentials. We find modifications that are present at
the time the CMB is formed are tightly constrained through their impact on the
well-measured CMB acoustic peaks. By contrast, constraints on late-time
modifications to the growth history, as might arise if modifications are
related to the onset of cosmic acceleration, are far weaker, but remain
consistent with Lambda CDM at the 95% confidence level. For these late-time
modifications we find that differences in the evolution on large and small
scales could provide an interesting signature by which to search for modified
growth histories with future wide angular coverage, large scale structure
surveys.
