2026/07/27 by An Ky Nguyen, Yuri Nikolayevsky
#math.DG
All Killing tensor fields on the spaces of constant curvature and on the complex projective space are decomposable, that is, can be represented as the sum of symmetric tensor products of Killing vector fields (equivalently, every polynomial integral of the geodesic flow is a polynomial in the linear integrals). This is no longer true for quadratic Killing tensor fields on the quaternionic projective spaces ℍ Pn, n ≥ 3, and on the Cayley projective plane \mathbbO P2. We prove that for the real Grassmannians and for the spaces SL(n)/SO(n), all quadratic Killing tensor fields are decomposable.