Joint Minkowski Functionals and Bispectrum Constraints on
  Non-Gaussianity in the CMB
  Two of the most commonly used tools to constrain the primordial
non-Gaussianity are the bispectrum and the Minkowski functionals of CMB
temperature anisotropies. These two measures of non-Gaussianity in principle
provide distinct (though correlated) information, but in the past constraints
from them have only been loosely compared, and not statistically combined. In
this work we evaluate, for the first time, the covariance matrix between the
local non-Gaussianity coefficient fnl estimated through the bispectrum and
Minkowski functionals. We find that the estimators are positively correlated,
with corerlation coefficient r ~ 0.3. Using the WMAP7 data to combine the two
measures and accounting for the point-source systematics, we find the combined
constraint fnl=37+/-28, which has a ~20% smaller error than either of the
individual constraints.
