Minimum degree thresholds for bipartite graph tiling
  For any bipartite graph $H$, we determine a minimum degree threshold for a balanced bipartite graph $G$ to contain a perfect $H$-tiling. We show that this threshold is best possible up to a constant depending only on $H$. Additionally, we prove a corresponding minimum degree threshold to guarantee that $G$ has an $H$-tiling missing only a constant number of vertices. Our threshold for the perfect tiling depends on either the chromatic number $\chi(H)$ or the critical chromatic number $\chi_{cr}(H)$ while the threshold for the almost perfect tiling only depends on $\chi_{cr}(H)$. Our results answer two questions of Zhao. They can be viewed as bipartite analogs to the results of Kuhn and Osthus and of Shokoufandeh and Zhao. 
Albert Bush and Yi Zhao
math.CO