Effect of Priomordial non-Gaussianities on Galaxy Clusters Scaling
  Relations
  Galaxy clusters are a valuable source of cosmological information. Their
formation and evolution depends on the underlying cosmology and on the
statistical nature of the primordial density fluctuations. In this work we
investigate the impact of primordial non-gaussianities (PNG) on the scaling
properties of galaxy clusters. We performed a series of cosmological
hydrodynamic N-body simulations featuring adiabatic gas physics and different
levels of non-Gaussian initial conditions within the $\Lambda$CDM framework. We
focus on the T-M, S-M, Y-M and Yx-M scalings relating the total cluster mass
with temperature, entropy and SZ cluster integrated pressure that reflect the
thermodynamical state of the intra-cluster medium. Our results show that PNG
have an impact on cluster scalings laws. The mass power-law indexes of the
scalings are almost unaffected by the existence of PNG but the amplitude and
redshift evolution of their normalizations are clearly affected. The effect is
stronger for the evolution of the Y-M and Yx-M normalizations, which change by
as much as 22% and 16% when $f_{NL}$ varies from -500 to 500, respectively.
These results are consistent with the view that positive/negative $f_{NL}$
affect cluster profiles due to an increase/decrease of cluster concentrations.
At low values of $f_{NL}$, as suggested by present Planck constraints on a
scale invariant $f_{NL}$, the impact on the scalings normalizations is only a
few percent, which is small when compared with the effect of additional gas
physics and other cosmological effects such as dark energy. However if $f_{NL}$
is in fact a scale dependent parameter, PNG may have larger positive/negative
amplitudes at clusters scales and therefore our results suggest that PNG should
be taken into account when galaxy cluster data is used to infer cosmological
parameters or to asses the constraining power of future cluster surveys.
