Rearrangement-invariant hulls of weighted Lebesgue spaces

Abstract: We characterize the rearrangement-invariant hull, with respect to a given measure $\mu$, of weighted Lebesgue spaces. The solution leads us to first consider when this space is contained in the sum of $(L^1 + L^\infty)(R, \mu)$ and the final condition is given in terms of embeddings for weighted Lorentz spaces.