On the geometry of holomorphic curves and complex surface

Abstract

We investigate the geometry of holomorphic curves and complex surfaces from the perspective of singularity theory. We show that, with a suitable choice of a complex bilinear symmetric form, the families of functions and mappings that measure the contact between curves or surfaces and model objects become holomorphic. This allows the application of singularity theory, yielding analogues of classical results from the real case. Our approach enables the definition of geometric invariants of curves, which we call the $C$-curvature and $C$-torsion, as well as surface invariants such as the $C$-principal curvature and $C$-Gaussian curvature. It also gives geometric meaning to the complexification of of the families measuring contact of analytic surfaces in $\mathbb R^3$ with lines, planes and spheres.