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arXiv · 1402.7192

Sections of functions and Sobolev type inequalities

V. I. Kolyada
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Abstract

We study functions of two variables whose sections by the lines parallel to the coordinate axis satisfy Lipschitz condition of the order $0<\a\le 1.$ We prove that if for a function $f$ the $\operatorname{Lip} \a-$ norms of these sections belong to the Lorentz space $L^{p,1}(\R) \,(p=1/\a),$ then $f$ can be modified on a set of measure zero so as to become bounded and uniformly continuous on $\R^2.$ For $\a=1$ this gives an extension of Sobolev's theorem on continuity of functions of the space $W_1^{2,2}(\R^2)$. We show that the exterior $L^{p,1}-$ norm cannot be replaced by a weaker Lorentz norm $L^{p,q}$ with $q>1$.

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V. I. Kolyada. 2014-02-28. Sections of functions and Sobolev type inequalities. https://arxiv.org/abs/1402.7192

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