In this dissertation, we study the geometric rigidity of compact $(\lambda,n+m)$- Einstein manifolds $(M^{n},g,f)$, $n\geq4,$ under the Bach-flat condition. Following the methodological approach of Chen and He, we analyze the behavior of the Weyl tensor and the potential function $f$ on these spaces. It is shown that the vanishing of the Bach tensor rigidly restricts the geometry of the manifold, implying that the space is locally conformally flat if $n=4, or that it has a harmonic Weyl tensor and zero radial Weyl curvature if $n\geq4$. Finally, we detail the global classification resulting from these properties for the case where the parametrer $m\neq1$ and the constant $\lambda$ is positive.