An area formula in metric spaces
Tom 124 / 2011
Colloquium Mathematicum 124 (2011), 275-283 MSC: Primary 28A75. DOI: 10.4064/cm124-2-11
We present an area formula for continuous mappings between metric spaces, under minimal regularity assumptions. In particular, we do not require any notion of differentiability. This is a consequence of a measure-theoretic notion of Jacobian, defined as the density of a suitable “pull-back measure”. Finally, we give some applications and examples.