Title: Beyond recursion operators,
Abstract: We briefly recall the history of the Nijenhuis torsion of (1,1)-tensors on
manifolds and of the lesser-known Haantjes torsion. We then show how the
Haantjes manifolds of Magri and the symplectic-Haantjes structures of Tempesta
and Tondo generalize the classical approach to integrable systems in the
bi-hamiltonian and symplectic-Nijenhuis formalisms, the sequence of powers of
the recursion operator being replaced by a family of commuting Haantjes
operators.