Compact positive multilinear operators on Banach lattices

Abstract

Let $1 < p_1, \ldots, p_n < \infty, 1\leq q < \infty$ be such that $\sum\limits_{i=1}^n \frac{1}{p_i} < \frac{1}{q}$ and let $\mu_1, \ldots, \mu_n, \nu$ be arbitrary measures. Generalizing known linear and multilinear results, we prove that all positive $n$-linear operators from $\ell_{p_1} \times \cdots \times \ell_{p_n}$ to $L_q(\nu)$ and from $L_{p_1}(\mu_1) \times \cdots \times L_{p_1}(\mu_n)$ to $\ell_{q}$ are compact. This result, along with other related ones concerning free Banach lattices, shall emerge as consequences of some facts we prove about $M$-weakly compact multilinear operators on Banach lattices.