Duality for logarithmic interpolation spaces when 0 < q < 1 and applications

We work with spaces (A0;A1)θ;q;A which are logarithmic perturbations of the real interpolation spaces. We determine the dual of (A0;A1)θ;q;A when0 < q < 1. As we show, if θ = 0 or 1 then the dual space depends on the relationship between q and A. Furthermore we apply the abstract results to compute the dual space of Besov spaces of logarithmic smoothness and the dual space of spaces of compact operators in a Hilbert space which are closeto the Macaev ideals