Hodge filtration and Hodge ideals for $\mathbb{Q}$-divisors with weighted homogeneous isolated singularities

Abstract

We give an explicit formula for the Hodge filtration on the ${\mathcal{D}}_X$-module $O_X(\ast Z)f^{1-\alpha }$ associated to the effective $\mathbb{Q}$-divisor $D=\alpha \cdot Z$, where $0<\alpha \le 1$ and $Z=(f=0)$ is an irreducible hypersurface defined by $f$, a weighted homogeneous polynomial with an isolated singularity at the origin. In particular this gives a formula for the Hodge ideals of $D$. We deduce a formula for the generating level of the Hodge filtration, as well as further properties of Hodge ideals in this setting. We also extend the main theorem to the case when $f$ is a germ of holomorphic function that is convenient and has non-degenerate Newton boundary.

23 pages; add an assumption in the nondegenerate case that f need to be convenient; add Lemma 5.3 and add a proof of Lemma 5.4