Positive Quaternion Kaehler Manifolds are Riemannian manifolds with holonomy
contained in Sp(n)Sp(1) and with positive scalar curvature. Conjecturally, they
are symmetric spaces. We prove this conjecture in dimension 20 under additional
assumptions and we provide recognition theorems for quaternionic projective
spaces (in low dimensions) as well as the real Grassmanian (which is Positive
Quaternion Kaehler).
Positive Quaternion Kaehler Manifolds are Riemannian manifolds with holonomy
contained in Sp(n)Sp(1) and with positive scalar curvature. Conjecturally, they
are symmetric spaces. We offer a new approach to this field of study via
Rational Homotopy Theory, thereby proving the formality of Positive Quaternion
Kaehler Manifolds. This result is established by means of an in-depth
investigation on how formality behaves under spherical fibrations.