Smoothness of indicator functions of some sets in Wiener spaces (Q1583568)

The authors prove the following result: Let \(A\) be a ball in the classical Wiener space defined by the sup-norm or the pseudo Sobolev norm, then \(\chi_A\in E^p_\alpha\) for \(p\alpha<1\) and \(\chi_A\notin E^p_\alpha\) for \(p\alpha>1\).