A robust version of the multipartite Hajnal--Szemerédi theorem

Abstract: In this note we show the following strengthening of a multipartite version of the Hajnal--Szemer\'edi theorem. For an integer $r \ge 3$ and $\gamma > 0$, there exists a constant $C$ such that if $p\ge Cn^{-2/r}(\log n)^{1/{r \choose 2}}$ and $G$ is a balanced $r$-partite graph with each vertex class of size $n$ and $\delta^\ast(G)\ge (1-1/r+\gamma)n$, then with high probability the random subgraph $G(p)$ of $G$ contains a $K_r$-factor. We also use it to derive corresponding transversal versions.