We show that a metric space X admits no sensitive commutative group action if it satisfies the following two conditions: (1) X has property S, that is, for each ε > 0 there exists a cover of X which consists of finitely many connected sets with diameter less than ε; (2) X contains a free n-network, that is, there exists a nonempty open set W in X having no isolated point and n ∈ ℕ such that, for any nonempty open set U ⊂ W, there is a nonempty connected open set V ⊂ U such that the boundary contains at most n points. As a corollary, we show that no Peano continuum containing a free dendrite admits a sensitive commutative group action. This generalizes some previous results in the literature.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-fm217-1-1, author = {Jiehua Mai and Enhui Shi}, title = {A class of spaces that admit no sensitive commutative group actions}, journal = {Fundamenta Mathematicae}, volume = {219}, year = {2012}, pages = {1-12}, zbl = {1251.54032}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-fm217-1-1} }
Jiehua Mai; Enhui Shi. A class of spaces that admit no sensitive commutative group actions. Fundamenta Mathematicae, Tome 219 (2012) pp. 1-12. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-fm217-1-1/