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We prove a Harnack inequality for positive solutions of a parabolic equation with slow anisotropic spatial diffusion. After identifying its natural scalings, we reduce the problem to a Fokker-Planck equation and construct a self-similar…

偏微分方程分析 · 数学 2021-05-06 Simone Ciani , Sunra Mosconi , Vincenzo Vespri

We study a porous medium equation with fractional potential pressure: $$ \partial_t u= \nabla \cdot (u^{m-1} \nabla p), \quad p=(-\Delta)^{-s}u, $$ for $m>1$, $0<s<1$ and $u(x,t)\ge 0$. The problem is posed for $x\in \mathbb{R}^N$, $N\geq…

偏微分方程分析 · 数学 2015-06-15 Diana Stan , Félix del Teso , Juan Luis Vázquez

Let $\Omega$ be a domain in $\mathbb R^N$, where $N \ge 2$ and $\partial\Omega$ is not necessarily bounded. We consider two fast diffusion equations $\partial_t u= \mbox{div}(|\nabla u|^{p-2}{\nabla u})$ and $\partial_t u= \Delta u^{m}$,…

偏微分方程分析 · 数学 2014-05-28 Shigeru Sakaguchi

A new transformation for radially symmetric solutions to the subcritical fast diffusion equation with spatially inhomogeneous source $$ \partial_tu=\Delta u^m+|x|^{\sigma}u^p, $$ posed for $(x,t)\in\mathbb{R}^N\times(0,\infty)$ and with…

偏微分方程分析 · 数学 2025-02-20 Razvan Gabriel Iagar , Ariel Sánchez

Let $n\geq 3$, $0< m<\frac{n-2}{n}$ and $T>0$. We construct positive solutions to the fast diffusion equation $u_t=\Delta u^m$ in $\mathbb{R}^n\times(0,T)$, which vanish at time $T$. By introducing a scaling parameter $\beta$ inspired by…

偏微分方程分析 · 数学 2018-11-13 Kin Ming Hui , Soojung Kim

Let $(M^{n},g)$ be a complete Riemannian manifold. In this paper, we establish a space-time gradient estimates for positive solutions of nonlinear parabolic equations $$\partial_{t}u(x,t)=\Delta u(x,t)+a u(x,t)(\log u(x,t))^b +…

微分几何 · 数学 2022-06-28 Shahroud Azami

We prove expansion of positivity and reduction of the oscillation results to the local weak solutions to a doubly nonlinear anisotropic class of parabolic differential equations with bounded and measurable coefficients, whose prototype is…

偏微分方程分析 · 数学 2025-07-10 Simone Ciani , Eurica Henriques , Mariia Savchenko , Igor I. Skrypnik

A set of pointwise estimates are established for local solutions to nonlocal diffusion equations with a drift term. In particular, our Harnack estimates are the first ones for such equations, and our H\"older regularity refines certain…

偏微分方程分析 · 数学 2025-01-14 Naian Liao

We study linear time fractional diffusion equations in divergence form of time order less than one. It is merely assumed that the coefficients are measurable and bounded, and that they satisfy a uniform parabolicity condition. As the main…

偏微分方程分析 · 数学 2010-11-13 Rico Zacher

We obtain new estimates for the solution of both the porous medium and the fast diffusion equations by studying the evolution of suitable Lipschitz norms. Our results include instantaneous regularization for all positive times, long-time…

偏微分方程分析 · 数学 2023-09-26 Noemi David , Filippo Santambrogio

We study a nonlocal aggregation equation with degenerate diffusion, set in a periodic domain. This equation represents the generalization to $m > 1$ of the McKean-Vlasov equation where here the "diffusive" portion of the dynamics are…

偏微分方程分析 · 数学 2012-04-19 Lincoln Chayes , Inwon Kim , Yao Yao

This paper is concerned with the weak solution for the fast diffusion equation with absorption and singularity in the form of $u_t=\triangle u^m -u^p$. We first prove the existence and decay estimate of weak solution when the fast diffusion…

偏微分方程分析 · 数学 2024-05-14 Changping Xie , Shaomei Fang , Ming Mei , Yuming Qin

We study the asymptotic large time behavior of singular solutions of the fast diffusion equation $u_t=\Delta u^m$ in $({\mathbb R}^n\setminus\{0\})\times(0,\infty)$ in the subcritical case $0<m<\frac{n-2}{n}$, $n\ge3$. Firstly, we prove the…

偏微分方程分析 · 数学 2015-08-11 Kin Ming Hui , Soojung Kim

This paper deals with the space-homogenous Landau equation with very soft potentials, including the Coulomb case. This nonlinear equation is of parabolic type with diffusion matrix given by the convolution product of the solution with the…

偏微分方程分析 · 数学 2024-01-24 François Golse , Cyril Imbert , Sehyun Ji , Alexis F. Vasseur

We reduce the problem of proving decay estimates for viscosity solutions of fully nonlinear PDEs to proving analogous estimates for solutions of one-dimensional ordinary differential inequalities. Our machinery allow the ellipticity to…

偏微分方程分析 · 数学 2025-06-17 Niklas L. P. Lundström , Marcus Olofsson , Jesper Singh

We study the homogeneous Cauchy-Dirichlet Problem (CDP) for a nonlinear and nonlocal diffusion equation of singular type of the form $\partial_t u =-\mathcal{L} u^m$ posed on a bounded Euclidean domain $\Omega\subset\mathbb{R}^N$ with…

偏微分方程分析 · 数学 2022-08-01 Matteo Bonforte , Peio Ibarrondo , Mikel Ispizua

We prove sharp estimates for the decay in time of solutions to a rather general class of non-local in time subdiffusion equations on a bounded domain subject to a homogeneous Dirichlet boundary condition. Important special cases are the…

偏微分方程分析 · 数学 2013-10-02 Vicente Vergara , Rico Zacher

We investigate the regularity of local weak solutions to evolution equations of the form \[…

偏微分方程分析 · 数学 2026-04-23 Pasquale Ambrosio , Simone Ciani , Giovanni Cupini

In this paper, we study local uniform continuity of nonnegative weak solutions to degenerate diffusion-drift equations in the form \[ u_{t} = \Delta u^{m} + \nabla\cdot \left( B (x,t) \, u\right), \quad \text{for } m \geq 1 \] assuming a…

偏微分方程分析 · 数学 2019-06-13 Sukjung Hwang , Yuming Paul Zhang

We obtain a priori estimates with best constants for the solutions of the fractional fast diffusion equation $u_t+(-\Delta)^{\sigma/2}u^m=0$, posed in the whole space with $0<\sigma<2$, $0<m\le 1$. The estimates are expressed in terms of…

偏微分方程分析 · 数学 2013-10-14 Juan Luis Vázquez , Bruno Volzone