On ψ- interpolation spaces

In this paper the sequence Banach space ψ (Z) is defined for a class of convex functions ψ , and properties of the Kand Jinterpolation spaces (E0,E1)θ ,ψ,K and (E0,E1)θ ,ψ,J for a Banach couple E = (E0,E1) and θ ∈ (0,1) are studied. Mathematics subject classification (2000): 46B70.