Confronting the concordance model of cosmology with Planck data
  We confront the concordance (standard) model of cosmology, the spatially flat
$\Lambda$CDM Universe with power-law form of the primordial spectrum with
Planck CMB angular power spectrum data searching for possible smooth deviations
beyond the flexibility of the standard model. The departure from the
concordance cosmology is modeled in the context of Crossing statistic and
statistical significance of this deviation is used as a measure to test the
consistency of the standard model to the Planck data. Derived Crossing
functions suggest the presence of some broad features in angular spectrum
beyond the expectations of the concordance model. Our results indicate that the
concordance model of cosmology is consistent to the Planck data only at 2 to
3$\sigma$ confidence level if we allow smooth deviations from the angular power
spectrum given by the concordance model. This might be due to random
fluctuations or may hint towards smooth features in the primordial spectrum or
departure from another aspect of the standard model. Best fit Crossing
functions indicate that there are lack of power in the data at both low-$\ell$
and high-$\ell$ with respect to the concordance model. This hints that we may
need some modifications in the foreground modeling to resolve the significant
inconsistency at high-$\ell$. However, presence of some systematics at
high-$\ell$ might be another reason for the deviation we found in our analysis.
