Constrained simulations of the local universe: II. The nature of the
  local Hubble flow
  Using a suite of N-body simulations in different Cold Dark Matter (CDM)
scenarios, with cosmological constant (\LCDM) and without (OCDM, SCDM), we
study the Hubble flow (\sigh) in Local Volumes (LV) around Local Group (LG)
like objects found in these simulations, and compare the numerical results with
the most recent observations. We show that \LCDM and OCDM models exhibit the
same behavior of \sigh. Hence, we demonstrate that the observed coldness of the
Hubble flow is not likely to be a manifestation of the dark energy, contrary to
previous claims. The coldness does not constitute a problem by itself but it
poses a problem to the standard \LCDM model only if the mean density within the
Local Volume is greater than twice the mean matter cosmic density. The lack of
blueshifted galaxies in the LV, outside of the LG can be considered as another
manifestation of the coldness of the flow. Finally, we show that the main
dynamical parameter that affects the coldness of the flow is the relative
isolation of the LG, and the absence of nearby Milky Way like objects within a
distance of about $3\mpc$.
