Grid Minors in Damaged Grids
				
										Keywords:
				
				
																		graph theory, 													grid graphs, 													graph minors, 													subgraphs, 													shallow minors, 													treewidth, 													vertex deletion															
			
			
										Abstract
We prove upper and lower bounds on the size of the largest square grid graph that is a subgraph, minor, or shallow minor of a graph in the form of a larger square grid from which a specified number of vertices have been deleted. Our bounds are tight to within constant factors. We also provide less-tight bounds on analogous problems for higher-dimensional grids.