Candidate for the role of higher-spin symmetry

Infinite-dimensional non-abelian superalgebras, related to interacting massless higher-spin fields of all spins s≥3/2, are proposed. Conditions are formulated that provide uniqueness for these higher-spin superalgebras, denoted as shs/sub rho/(1) ( rho = 0 or 1). Among these conditions, the major role is played by the requirement that linearized curvatures of shs/sub rho/(1) coincide with the linearized higher-spin curvatures obtained previously. Subalgebras and contractions of shs/sub rho/(1) are considered. A higher-spin interaction, which is introduced in terms of the shs/sub rho/(1) curvatures, is discussed briefly. It is found that a gravitational interaction of massless higher spins requires non-analyticity in the cosmological constant