The effect of interacting dark energy on local measurements of the
  Hubble constant
  In the current state of cosmology, where cosmological parameters are being
measured to percent accuracy, it is essential to understand all sources of
error to high precision. In this paper we present the results of a study of the
local variations in the Hubble constant measured at the distance scale of the
Coma Cluster, and test the validity of correcting for the peculiar velocities
predicted by gravitational instability theory. The study is based on N-body
simulations, and includes models featuring a coupling between dark energy and
dark matter, as well as two $\Lambda$CDM simulations with different values of
$\sigma_8$. It is found that the variance in the local flows is significantly
larger in the coupled models, which increases the uncertainty in the local
measurements of the Hubble constant in these scenarios. By comparing the
results from the different simulations, it is found that most of the effect is
caused by the higher value of $\sigma_8$ in the coupled cosmologies, though
this cannot account for all of the additional variance. Given the discrepancy
between different estimates of the Hubble constant in the universe today,
cosmological models causing a greater cosmic variance is something that we
should be aware of.
