Abstract
We show that in a Q-doubling space (X, d, µ), Q > 1, which satisfies a chain condition, if we have a Q-Poincaré inequality for a pair of functions (u, g) where g ∈ L Q(X), then u has Lebesgue points \(\mathcal{H}^h \)-a.e. for \(h(t) = \log ^{1 - Q - \varepsilon } (1/t)\). We also discuss how the existence of Lebesgue points follows for u ∈ W 1,Q(X) where (X, d, µ) is a complete Q-doubling space supporting a Q-Poincaré inequality for Q > 1.
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Karak, N., Koskela, P. Lebesgue points via the Poincaré inequality. Sci. China Math. 58, 1697–1706 (2015). https://doi.org/10.1007/s11425-015-5001-9
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DOI: https://doi.org/10.1007/s11425-015-5001-9