Interpolation of operators of weak type $(ϕ_0, ψ_0, ϕ_1, ψ_1)$ in Lorentz spaces

Abstract

We prove theorems of interpolation of quasilinear operators of weak type (φ₀ , ψ₀ , φ₁ , ψ₁ ) in the Lorentz spaces. The operators considered are the analogs of the Calderon and Benett operators for concave and convex functions φ₀ (t), ψ₀ (t), φ₁ (t), ψ₁ (t).