Free geometric equations for higher spins (TOPCITE: 187 citazioni su SPIRES HEP)

We show how allowing non-local terms in the field equations of symmetric tensors uncovers a neat geometry that naturally generalizes the Maxwell and Einstein cases. The end results can be related to multiple traces of the generalized Riemann curvatures R α1···αs ;β1···βs introduced by de Wit and Freedman, divided by suitable powers of the D’Alembertian operator ✷. The conventional local equations can be recovered by a partial gauge fixing involving the trace of the gauge parameters Λα1···αs−1 , absent in the Fronsdal formulation. The same geometry underlies the fermionic equations, that, for all spins s +1/2, can be linked via the operator ∂ slash/Box to those of the spin-s bosons.