Matrix Subspaces of $L_1$

TL;DR

This paper investigates the structure of matrix subspaces within $L_1$, demonstrating that certain matrix spaces with specific unconditional basic sequences embed into $L_1$, extending recent theoretical results.

Contribution

It generalizes recent embedding results by establishing conditions under which matrix spaces with unconditional bases embed into $L_1$.

Findings

Matrix spaces with $r$-concave and $p$-convex bases embed into $L_1$.

Generalization of Prochno and Schütt's recent results.

Provides new insights into the structure of matrix subspaces in $L_1$.

Abstract

If $E=\{e_i\}$ and $F=\{f_i\}$ are two 1-unconditional basic sequences in $L_1$ with $E$ $r$-concave and $F$ $p$-convex, for some $1\le r<p\le 2$, then the space of matrices $\{a_{i,j}\}$ with norm $\|\{a_{i,j}\}\|_{E(F)}=\big\|\sum_k \|\sum_l a_{k,l}f_l\|e_k\big\|$ embeds into $L_1$. This generalizes a recent result of Prochno and Sch\"utt.