Singularities in any Characteristic

TL;DR

This paper provides a comprehensive overview of hypersurface singularities over arbitrary real valued fields, extending classical and formal power series theories, and includes new classification results in positive characteristic.

Contribution

It introduces new classification results for simple singularities in positive characteristic and extends existing theories to a broader algebraic setting.

Findings

Classification of contact simple singularities in positive characteristic

Complete proofs of new results in the general setting

Unification of classical and formal power series approaches

Abstract

We give an overview of the fundamental definitions and results concerning hypersurface singularities, defined by convergent power series over an arbitrary real valued field. This approach combines, on the one hand, the classical case of analytic power series over the complex numbers with formal power series over arbitrary fields, but on the other hand, it goes significantly beyond that. Besides general definitions and basic results, we report on the classification of contact simple and right simple singularities in positive characteristic. Some of the results are new in this general setting, for which we provide complete proofs.