Inserted: 16 may 2017
Last Updated: 16 may 2017
Journal: Proceedings of the American Mathematical Society
Volume: 141 (2013)
We show if a metric measure space admits a differentiable structure then porous sets have measure zero and hence the measure is pointwise doubling. We then give a construction to show if we only require an approximate differentiable structure the measure need no longer be pointwise doubling.