The helical transform and the a.e. convergence of Fourier series
Idris Assani · Illinois Journal of Mathematics · 1993
Bytaking an invariant function (i.e., f q f) the discontinuity property at 0 of E eike k k shows easily that not all functions satisfy the strong Wiener-Wintner property (S.W.W.).This property (S.W.W.) is more likely to hold when we are outside the Kronecker factor of o (i.e., the closure of the linear span of the