Gyration Stability for Projective Planes

TL;DR

This paper investigates the concept of gyration stability in manifolds, specifically focusing on projective planes, and provides a complete classification for complex, quaternionic, and octonionic cases.

Contribution

It offers a comprehensive analysis of gyration stability for various projective planes up to homotopy, extending previous work on quaternionic projective planes.

Findings

Complex projective plane is gyration stable.

Quaternionic and octonionic projective planes are not gyration stable.

Complete classification of gyration stability for these manifolds.

Abstract

Gyrations are operations on manifolds that arise in geometric topology, where a manifold $M$ may exhibit distinct gyrations depending on the chosen twisting. For a given $M$, we ask a natural question: do all gyrations of $M$ share the same homotopy type regardless of the twisting? A manifold with this property is said to have gyration stability. Inspired by recent work by Duan, which demonstrated that the quaternionic projective plane is not gyration stable with respect to diffeomorphism, we explore this question for projective planes in general. We obtain a complete description of gyration stability for the complex, quaternionic, and octonionic projective planes up to homotopy.