Quaternion-Kähler symmetric space

A Quaternion-Kähler symmetric space is a specific type of geometric structure that arises in differential geometry and mathematical physics. It is a type of Riemannian manifold that possesses a rich structure related to both quaternionic geometry and Kähler geometry. To understand what a Quaternion-Kähler symmetric space is, let's break down the terms: 1. **Quaternionic Geometry**: Quaternionic geometry is an extension of complex geometry, incorporating quaternions, which are a number system that extends complex numbers.