PDE Seminar Abstracts

Almost everywhere matters

Michael Cowling
University of New South Wales
Mon 21st Aug 2017, 2-3pm, Carslaw Room 829 (AGR)


Suppose that F is a homeomorphism of 2 that is differentiable almost everywhere. If F(x,y) = (f(x),g(y)), then it is clear that the derivative of F is given by a diagonal matrix when it exists. Is the converse true? We explain how the distinction between differentiable everywhere and differentiable almost everywhere is important in this question.