Structure formation simulations with momentum exchange: alleviating
  tensions between high-redshift and low-redshift cosmological probes
  Persisting tensions between the cosmological constraints derived from
low-redshift probes and the ones obtained from temperature and polarisation
anisotropies of the Cosmic Microwave Background -- although not yet providing
compelling evidence against the $\Lambda $CDM model -- seem to consistently
indicate a slower growth of density perturbations as compared to the
predictions of the standard cosmological scenario. Such behavior is not easily
accommodated by the simplest extensions of General Relativity, such as f(R)
models, which generically predict an enhanced growth rate. In the present work
we present the outcomes of a suite of large N-body simulations carried out in
the context of a cosmological model featuring a non-vanishing scattering cross
section between the dark matter and the dark energy fields, for two different
parameterisations of the dark energy equation of state. Our results indicate
that these Dark Scattering models have very mild effects on many observables
related to large-scale structures formation and evolution, while providing a
significant suppression of the amplitude of linear density perturbations and
the abundance of massive clusters. Our simulations therefore confirm that these
models offer a promising route to alleviate existing tensions between
low-redshift measurements and those of the CMB.
