Relative Cohen-Macaulayness and relative unmixedness of bigraded modules
  In this paper we study the finitely generated bigraded modules over a standard bigraded polynomial ring which are relative Cohen-Macaulay or relative unmixed with respect to one of the irrelevant bigraded ideals. A generalization of Reisner's criterion for Cohen-Macaulay simplicial complexes is considered. 
Maryam Jahangiri and Ahad Rahimi
math.AC math.AG