On the conservative pasting lemma
  Several perturbation tools are established in the volume preserving setting allowing for the pasting, extension, localized smoothing and local linearization of vector fields. The pasting and local linearization hold in all classes of regularity ranging from $C^{1}$ to $C^{\infty}$ (H\"older included). For diffeomorphisms, a conservative linearized version of Franks lemma is proved in the $C^{r,\alpha}$ ($r\in\mathbb{Z}^+$, $0<\alpha <1$) and $C^{\infty}$ settings, the resulting diffeomorphism having the same regularity as the original one. 
Pedro Teixeira
math.DS