I need to evaluate the Einstein tensor/ Ricci tensor and others in a perturbed metric. Suppose my metric is
$g_{ab} =\eta_{ab} +h_{ab}$, where $\eta$ is the Minkowski metric, and $h$ is a small perturbation. I want to find the first order correction to the aforesaid metrics.
Is there any software/package that is capable of doing this kind of symbolic computations?