Castelnuovo-Mumford regularity and arithmetic Cohen-Macaulayness of   complete bipartite subspace arrangements
  We give the Castelnuovo-Mumford regularity of arrangements of (n-2)-planes in P^n whose incidence graph is a sufficiently large complete bipartite graph, and determine when such arrangements are arithmetically Cohen-Macaulay. 
Zach Teitler, Douglas A. Torrance
math.AG math.AC