On Teissier’s example of an equisingularity class that cannot be defined over the rationals
Volume 135 / 2025
Annales Polonici Mathematici 135 (2025), 265-279
MSC: Primary 32S25; Secondary 32S15, 14B05
DOI: 10.4064/ap241208-25-4
Published online: 27 October 2025
Abstract
A result of Teissier says that the cone over one of classical polygon examples in the real projective space gives, by complexification, a surface singularity which is not Whitney equisingular to a singularity defined over the field $\mathbb Q$ of rational numbers. In this note we correct the example and give a complete proof of Teissier’s result.
