Local quartic interaction of scalars with higher spin gauge fields and commutator of linear gauge transformations

Some special case of local quartic interaction of higher spin gauge field with a scalar field is considered. The nontrivial task of construction of interacting Lagrangian for the constrained higher spin field (physical gauge) was solved using the full power of Noether’s procedure. As a byproduct linear on-field gauge transformation is obtained and the corresponding closure of commutator of transformation is analyzed. The right-hand side of this commutator is classified in respect to gauge transformations coming from cubic interactions of a scalar with different higher spin symmetric tensor fields and with mixed symmetry tensor field transformations.