We investigate the capabilities of perturbation theory in capturing non-linear effects of dark energy .
We test constant and evolving w models , as well as models involving momentum exchange between dark energy and dark matter .
Specifically , we compare perturbative predictions at 1-loop level against N-body results for four non-standard equations of state as well as varying degrees of momentum exchange between dark energy and dark matter .
The interaction is modelled phenomenologically using a time dependent drag term in the Euler equation .
We make comparisons at the level of the matter power spectrum and the redshift space monopole and quadrupole .
The multipoles are modelled using the Taruya , Nishimichi and Saito ( TNS ) redshift space spectrum .
We find perturbation theory does very well in capturing non-linear effects coming from dark sector interaction .
We isolate and quantify the 1-loop contribution coming from the interaction and from the non-standard equation of state .
We find the interaction parameter \xi amplifies scale dependent signatures in the range of scales considered .
Non-standard equations of state also give scale dependent signatures within this same regime .
In redshift space the match with N-body is improved at smaller scales by the addition of the TNS free parameter \sigma _ { v } .
To quantify the importance of modelling the interaction , we create mock data sets for varying values of \xi using perturbation theory .
This data is given errors typical of Stage IV surveys .
We then perform a likelihood analysis using the first two multipoles on these sets and a \xi = 0 modelling , ignoring the interaction .
We find the fiducial growth parameter f is generally recovered even for very large values of \xi both at z = 0.5 and z = 1 .
The \xi = 0 modelling is most biased in its estimation of f for the phantom w = -1.1 case .