Pfaffian Geometry and Indicial Singularities of Third-Order Linear ODEs
arXiv:2609.30748
Abstract
We study third-order linear differential equations through their associated Pfaffian and projective foliations. In the regular-singular setting, we introduce a Fuchs-adapted Pfaffian model in which the indicial polynomial appears directly in the special-fiber singular scheme, and Frobenius resonance acquires a projective geometric interpretation.