Nonholonomic simple \(\mathcal D\)-modules over projective varieties. (Q2499318)

Suppose that \(X\) is an irreducible smooth complex algebraic variety of dimension \(n\) and \(\mathcal D_X\) is the sheaf of rings of differential operators on \(X\). The dimension of the characteristic variety of a \(\mathcal D_X\)-module \(\mathcal M\) is greater or equal to \(n\). \(\mathcal M\) is holonomic if the dimension is equal to \(n\). It is shown that there exists a \(\mathcal D_X\)-module for which the dimension is equal to \(n+1\).