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Related papers: Differential Harnack Estimates for Fisher's Equati…

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Based on gradient estimates for the heat equation by Hamilton, we discover a backward in time Harnack inequality for positive solutions on compact manifolds without further restrictions such as boundedness or vanishing boundary value for…

Analysis of PDEs · Mathematics 2025-08-28 Juanling Lu , Yuting Wu , Qi S. Zhang

In this paper, we derive a general evolution formula for possible Harnack quantities. As a consequence, we prove several differential Harnack inequalities for positive solutions of backward heat-type equations with potentials (including the…

Differential Geometry · Mathematics 2008-05-23 Xiaodong Cao

In this paper we study the heat equation (of Hodge-Laplacian) deformation of $(p, p)$-forms on a K\"ahler manifold. After identifying the condition and establishing that the positivity of a $(p, p)$-form solution is preserved under such an…

Differential Geometry · Mathematics 2015-03-17 Lei Ni , Yanyan Niu

In this paper, we obtain Li-Yau type gradient estimates with time dependent parameter for positive solutions of the heat equation that are different with the estimates by Li-Xu \cite{LX} and Qian \cite{Qi}. As an application of the…

Differential Geometry · Mathematics 2018-07-30 Chengjie Yu , Feifei Zhao

We first give a logarithmic gradient estimate for positive solutions of Allen-Cahn equation on Riemannian manifolds with Ricci curvature bounded below. As its natural corallary, Harnack inequality and a Liouville theorem for classical…

Analysis of PDEs · Mathematics 2024-04-12 Zhihao Lu

In this paper, we consider a manifold evolving by a general geometric flow and study parabolic equation \[ (\Delta -q(x,t)-\partial_t)u(x,t)=A(u(x,t)),\quad (x,t)\in M\times [0,T]. \] We establish space-time gradient estimates for positive…

Differential Geometry · Mathematics 2024-04-16 Guangwen Zhao

We generalize Hamilton's matrix Li-Yau-type Harnack estimate for the Ricci flow by considering the space of all LYH (Li-Yau-Hamilton) quadratics that arise as curvature tensors of space-time connections satisfying the Ricci flow with…

Differential Geometry · Mathematics 2007-05-23 Bennett Chow , Dan Knopf

We establish Harnack's estimates for positive weak solutions to a mixed local and nonlocal doubly nonlinear parabolic equation. All results presented in this paper are provided together with quantitative estimates.

Analysis of PDEs · Mathematics 2022-09-05 Kenta Nakamura

In this paper we give both an historical and technical overview of the theory of Harnack inequalities for nonlinear parabolic equations in divergence form. We start reviewing the elliptic case with some of its variants and geometrical…

Analysis of PDEs · Mathematics 2019-01-31 F. G. Düzgün , S. Mosconi , V. Vespri

We prove a differential Harnack inequality for the Endangered Species Equation, a nonlinear parabolic equation. Our derivation relies on an idea related to the parabolic maximum principle. As an application of this inequality, we will show…

Analysis of PDEs · Mathematics 2015-06-30 Xiaodong Cao , Mark Cerenzia , Demetre Kazaras

We give an iterative method to estimate the disturbance of semi-wavefronts of the equation: $\dot{u}(t,x) = u''(t,x) +u(t,x)(1-u(t-h,x)),$ $x \in \mathbb{R},\ t >0;$ where $h>0.$ As a consequence, we show the exponential stability, with an…

Analysis of PDEs · Mathematics 2018-06-13 Rafael Benguria D. , Abraham Solar

We derive localized and global noncompact versions of Hamilton's gradient estimate for positive solutions to the heat equation on Riemannian manifolds with Ricci curvature bounded below. Our estimates are essentially optimal and…

Analysis of PDEs · Mathematics 2025-07-17 Loth Damagui Chabi , Philippe Souplet

Let $M$ be a closed Riemannian manifold with a family of Riemannian metrics $g_{ij}(t)$ evolving by geometric flow $\partial_{t}g_{ij} = -2{S}_{ij}$, where $S_{ij}(t)$ is a family of smooth symmetric two-tensors on $M$. In this paper we…

Differential Geometry · Mathematics 2014-02-19 Hongxin Guo , Masashi Ishida

New exact solutions for the heat equation with a polynomial non-linearity and for the Fisher equation are found. An extended class of non-linear heat equations admitting solitary wave solutions is found. The generalization of the Fisher…

Mathematical Physics · Physics 2007-07-25 Anatoly G. Nikitin , Tetyana A. Barannyk

Recently, the Li-Yau-type gradient estimates for positive solutions to parabolic equations \begin{equation} \partial_t u=\Delta u+\mathcal{R}_1u+\mathcal{R}_2u^{\alpha}+\mathcal{R}_3u(\log u)^{\beta},\notag \end{equation} under the general…

Differential Geometry · Mathematics 2025-06-19 Yijie Miao , Bin Shen

Gradient inequalities of the Hamilton type and the Li-Yau type for positive solutions to the heat equation are established from a probabilistic viewpoint, which simplifies the proofs of some results of Sun [{\it Pacific J. Math.}, 253…

Probability · Mathematics 2013-06-21 Li-Juan Cheng

We derive an interpolation version of constrained matrix Li-Yau-Hamilton estimate on K\"ahler manifolds. As a result, we first get a constrained matrix Li-Yau-Hamilton estimate for heat equation on a K\"ahler manifold with fixed K\"ahler…

Differential Geometry · Mathematics 2014-07-02 Xin-An Ren , Sha Yao , Li-Ju Shen , Guang-Ying Zhang

In this paper we prove gradient estimates of both elliptic and parabolic types, specifically, of Souplet-Zhang, Hamilton and Li-Yau types for positive smooth solutions to a class of nonlinear parabolic equations involving the Witten or…

Analysis of PDEs · Mathematics 2024-04-03 Ali Taheri , Vahideh Vahidifar

In this paper, we establish a new global Hessian matrix estimate for heat-type equations on Riemannian manifolds using a Bismut-type Hessian formula. Our results feature fully explicit coefficients as well as delay / growth rate functions.…

Analysis of PDEs · Mathematics 2025-06-16 Li-Juan Cheng , Rui-Yu Yang

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…

Analysis of PDEs · Mathematics 2021-05-06 Simone Ciani , Sunra Mosconi , Vincenzo Vespri