Calculus of Variations and Geometric Measure Theory

P. Baroni

Gradient continuity for $p(x)$-systems under minimal conditions on the exponent

created by baroni on 11 Mar 2025

[BibTeX]

Published Paper

Inserted: 11 mar 2025
Last Updated: 11 mar 2025

Journal: J. Differential Equations
Year: 2023
Doi: https://doi.org/10.1016/j.jde.2023.04.043
Links: Link

Abstract:

We consider solutions of $p(x)$-Laplacian systems with coefficients and we show that their gradient is continuous provided that the variable exponent has distributional gradient belonging to the Lorentz-Zygmund space $L^{n,1}\log L$ and that the gradient of the coefficient belongs to the Lorentz space $L^{n,1}$. The result is new since the useĀ of the sharp Sobolev embedding in rearrangement invariant spaces does not ensure the unique (up to now) known assumption for such result, namely the $\log$-Dini continuity of $p(\cdot)$ and the plain Dini continuity of the coefficient. Our approach relies on perturbation arguments and allows to slightly improve results in dimension two even for the case where $p(\cdot)$ is constant.


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