Griffiths transversality
= Griffiths transversality
{c}
{title2=$\nabla F^p\subseteq F^{p-1}\otimes\Omega_S^1$}
In a <variation of Hodge structure>, differentiation lowers the filtration index by at most one. In the relative de Rham construction, an absolute form of degree at least $p$ contributes, after extracting one base differential, a relative form of degree at least $p-1$. This filtration shift proves the condition for geometric variations.