Relative Regionally Proximal Tuples and Sensitivity
摘要
First we investigate relative n-regionally proximal tuples. Let π: (X, G) → (Y, G) be a Bronstein extension between minimal systems. It turns out that if (x1,…, xn) is a minimal point and (xi, xi+1) is relative regionally proximal for 1 ≤ i ≤ n − 1, then (x1,…, xn) is relative n-regionally proximal. We consider the relative versions of sensitivity, including relative n-sensitivity and relative block ℱt-n-sensitivity, where ℱt is the family of thick sets. We show that π is relatively n-sensitive if and only if the relative n-regionally proximal relation contains a point whose coordinates are distinct, and the structure of π which is relatively n-sensitive but not relatively n + 1-sensitive is determined. We also characterize relatively block ℱt-n-sensitive via relative regionally proximal tuples.