Entropy Analysis of some Active Scalar Equations

Elie Abdo

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arXiv · 2608.24312

Entropy Analysis of some Active Scalar Equations

Elie Abdo

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Abstract

We study a broad family of active scalar equations with fractional dissipation on $\mathbb{R}^2$ and prove that their entropy diverges to $-\infty$ at a sharp rate of order $\log t$. The proof is based on a suitable regularization scheme, uniform entropy estimates, and a limiting argument via the Vitali convergence theorem. Our analysis introduces new fractional logarithmic Sobolev inequalities, weighted commutator estimates, and fractional moment bounds. These results provide a general framework for studying spatial decay and long-time dynamics of nonlocal nonlinear partial differential equations.

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Elie Abdo. 2026-08-25. Entropy Analysis of some Active Scalar Equations. https://arxiv.org/abs/2608.24312

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