A Note on Weak Banach Mean Equicontinuity

Consider a topological dynamical system $(X,T)$ endowed with the metric $d$. We introduce a novel function as $\overline{BF}(x,y) = \limsup_{n-m \to +\infty} \inf_{\sigma \in S_{n,m}} \frac{1}{n-m} \sum_{k=m}^{n-1} d(T^{k}x,T^{\sigma(k)}y)$, where the permutation group $S_{n,m}$ is utilized. It is demonstrated that $BF(x,y)$ exists when $x,y \in X$ are uniformly generic points. Leveraging this function, we introduce the concept of weak Banach mean equicontinuity and establish that the dynamical system $(X,T)$ exhibits weak Banach mean equicontinuity if and only if the uniform time averages $f_{B}^{*}(x) = \lim_{n-m \to +\infty} \frac{1}{n-m} \sum_{k=m}^{n-1} f(T^{k}x)$ are continuous for all $f \in C(X)$. Finally, we demonstrate that in the case of a transitive system, the equivalence between weak Banach mean equicontinuity and weak mean equicontinuity is established.