Differentiating along rectangles in lacunary directions
arXiv:1605.04734
Abstract
We show that, given some lacunary sequence of angles not converging too fast to zero, it is possible to build a rare differentiation basis of rectangles parallel to the axes that differentiates while the basis obtained from by allowing its elements to rotate around their lower left vertex by the angles , , fails to differentiate all Orlicz spaces lying between and .