A Novel $J_M$-Based Method for Interpolation in Metric Spaces

Abstract: We present a new interpolation method for metric spaces, termed the \emph{$J_M^{\prime}$-interpolated metric space}. Building on previous work where two interpolation methods were developed in analogy with Peetre's classical $K$ and $J$ methods, this approach introduces a distinct construction based on approximating sequences in the intersection space $X_0 \cap X_1$ equipped with the metric $J_M(1)$. The method defines a relative completion within the union space $X_0 \cup X_1$, yielding a well-defined interpolated metric space with controllable relationships between the $J_M$ and $K_M$ metrics. While we do not compare this method to the previously developed approaches nor explore its correspondence with classical interpolation functors in normed spaces, the construction enriches the set of tools available for metric-space interpolation theory. Furthermore, as expected, these methods still preserve the Lipschitz property of an operator between two interpolated spaces. Potential applications include general Nonlinear Analysis and Wasserstein-type spaces where the sequence-based nature of the method may provide practical advantages.