Nahuel Albarracín | Searcharxiv

arXiv2025

Lipschitz extensions of linear operators

Let $E, F, E_0$ be Banach spaces, with $E_0$ a subspace of $E$. For a maximal Banach operator ideal $\mathcal{A}$, we show that a linear operator from $E_0$ to $F$ can be extended to a linear operator from $E$ to $F$ that belongs to $\mathcal{A}$ if and only if it can be extended to a Lipschitz map from $E$ to $F$ belonging to a wide class of Lipschitz Banach operator ideals related with $\mathcal{A}$. As a consequence, we show that linear operators with special Lipschitz factorization through $\ell_{\infty}(Γ)$ has analogous linear factorization through $\ell_{\infty}(Γ)$.

math.FA↗

arXiv2023

On the Lipschitz operator ideal $\text{Lip}_{0}\circ \mathcal A\circ \text{Lip}_{0}$

We study a systematic way to produce a Lipschitz operator ideal from a Banach linear operator ideal $\mathcal A$. For maximal and minimal operator ideals $\mathcal A$, the Lipschitz maximal hull and minimal kernel of the Lipschitz operator ideals $\text{Lip}_0 \circ \mathcal A \circ \text{Lip}_0$ are investigated, respectively. Using ultraproduct techniques, we obtain the Lipschitz version of a result of Kürsten and Piestch which characterizes the maximal hull of any Lipschitz operator ideal. Among other results, we characterize the linear operators which belong to $\text{Lip}_0\circ \mathcal A\circ \text{Lip}_0$ which, in many cases, they are precisely those which are in $\mathcal A$. In particular, we give some cases in which a nonlinear factorization of linear operators implies a linear one, in terms of a given Banach linear operator ideal $\mathcal A$.

math.FA↗