Cosmological simulations of screened modified gravity out of the static
  approximation: effects on matter distribution
  In the context of scalar tensor theories for gravity, there is a universally
adopted hypothesis when running N-body simulations that time derivatives in the
equation of motion for the scalar field are negligible. In this work we propose
to test this assumption for one specific scalar-tensor model with a gravity
screening mechanism: the symmetron. To this end, we implemented the necessary
modifications to include the non-static terms in the N-body code Ramses. We
present test cases and results from cosmological simulations. Our main finding
when comparing static vs. non-static simulations is that the global power
spectrum is only slightly modified when taking into account the inclusion of
non-static terms. On the contrary, we find that the calculation of the local
power spectrum gives different measurements. Such results imply one must be
careful when assuming the quasi-static approximation when investigating the
environmental effects of modified gravity and screening mechanisms in structure
formation of halos and voids distributions.
