Free and nearly free surfaces in $P^3$

Abstract

We define the nearly free surfaces in $P^3$ and show that the Hilbert polynomial of the Milnor algebra of a free or nearly free surface in $P^3$ can be expressed in terms of the exponents. An analog of Saito's criterion of freeness in the case of nearly free divisors is proven and examples of irreducible free and nearly free surfaces are given.