, 4 ) Multiplet of N = 8 , d = 1 Supersymmetry Evgeny Ivanov

We construct a nonlinear version of the d=1 off-shell N=8 multiplet (4,8,4) , proceeding from a nonlinear realization of the superconformal group OSp(4⋆|4) in the N=8 , d=1 analytic bi-harmonic superspace. The new multiplet is described by a double-charged analytic superfield q1,1 subjected to some nonlinear harmonic constraints which are covariant under the OSp(4⋆|4) transformations. This superfield, together with the analytic superspace coordinates, parametrizes an analytic coset manifold of OSp(4⋆|4) and so is a Goldstone superfield. Any action of q1,1 breaks the superconformal symmetry but can still respect N=8 , d=1 Poincaré supersymmetry. We construct the most general class of such supersymmetric actions and find the general expression for the bosonic target metric in terms of the original analytic Lagrangian superfield density which is thus the target geometry prepotential. It also fully specifies the scalar potential. The metric is conformally flat and in the SO(4) invariant case is a deformation of the metric on S4 .