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arXiv · 1208.4350

An upper gradient approach to weakly differentiable cochains

Kai Rajala·Stefan Wenger
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Abstract

The aim of the present paper is to define a notion of weakly differentiable cochain in the generality of metric measure spaces and to study basic properties of such cochains. Our cochains are (sub-)linear functionals on a subspace of chains, and a suitable notion of chains in metric spaces is given by Ambrosio-Kirchheim's theory of metric currents. The notion of weak differentiability we introduce is in analogy with Heinonen-Koskela's concept of upper gradients of functions. In one of the main results of our paper, we prove continuity estimates for cochains with $p$-integrable upper gradient in $n$-dimensional Lie groups endowed with a left-invariant Finsler metric. Our result generalizes the well-known Morrey-Sobolev inequality for Sobolev functions. Finally, we prove several results relating capacity and modulus to Hausdorff dimension.

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Kai Rajala, Stefan Wenger. 2012-08-21. An upper gradient approach to weakly differentiable cochains. https://arxiv.org/abs/1208.4350

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