“…This area has been developed recently very extensively and along with these investigations, the theory of Lorentz spaces, including the studies of their geometric structure, has been evolved independently (e.g. [6,9,11,10,14,19,18,27]). For instance, in the papers [10,11] the authors characterized the embeddings between the spaces Γ p,w for different parameters p and w. As a consequence, they characterized the Köthe dual of this space, and gave new conditions for the boundedness of several operators (identity, Hardy-Littlewood maximal function, Hilbert transform, etc.)…”