  Several ongoing and upcoming large scale structure surveys aim to explore the
nonlinear regime of structure formation with high precision. Making reliable
cosmological inferences from these observations necessitates precise
theoretical modeling of the mildly nonlinear regime. In this work we explore
how the choice of nonlinear prescription would impact parameter estimation from
cosmic shear measurements for a Euclid-like survey. Specifically, we employ two
different nonlinear prescriptions of Haloft and the Effective Field Theory of
the Large Scale Structure and compare their measurements for the three
different cosmological scenarios of $\Lambda$CDM, $w$CDM and $(w_0,w_a)$CDM. We
also investigate the impact of different nonlinear cutoff schemes on parameter
estimation. We find that the predicted errors on most parameters shrink
considerably as smaller scales are included in the analysis, with the amount
depending on the nonlinear prescription and the cutoff scheme used. We use
predictions from the Halofit model to analyze the mock data from DarkSky
$N$-body simulations and quantify the parameter bias introduced in the
measurements due to the choice of nonlinear prescription. We observe that
$\sigma_8$ and $n_{\rm{s}}$ have the largest measurement bias induced by
inaccuracies of the Halofit model.
