A family of cohen-macaulay modules over singularities of type xt+ y3

摘要

LetKbe a field with charK#x2260; 3 and it two positive integers such that 1 #x2264;it/2,t#x2260; 3i. The classification problem for maximal Cohen-Macaulay modules overKX,Y/(Xt+Y3) is complicated ift#x2265; 6, because there exist parameter families of non-isomorphic maximal Cohen-Macaulay modules Sc, or GK, Yo, Ch.9 and DG). Here we describe parameter families of such modulesN, such that N/YN is a direct sum of copies ofKX/(Xi)KX/(Xt-i).