An alternative characterization of normed interpolation spaces between ${\ell }^1$ and ${\ell }^q$

Michael Cwikel, Per G. Nilsson

Given a constant $q\in (1,\infty )$, we study the following property of a normed sequence space $E$: ===================== If ${\left\{x_n\right\}}_{n\in \mathbb{N}}$ is an element o…