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Related papers: The Bramson delay in the non-local Fisher-KPP equa…

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We consider the Fisher-KPP equation with a non-local interaction term. Hamel and Ryzhik showed that in solutions of this equation, the front location at a large time $t$ is $\sqrt 2 t +o(t)$. We study the asymptotics of the second order…

Probability · Mathematics 2017-08-29 Sarah Penington

We consider the solution to the scalar Fisher-KPP equation with front-like initial data, focusing on the location of its level sets at large times, particularly their deviation from points moving at the known spreading speed. We consider an…

Analysis of PDEs · Mathematics 2024-10-11 Matthieu Alfaro , Thomas Giletti , Dongyuan Xiao

We consider a class of reaction-diffusion equations of Fisher-KPP type in which the nonlinearity (reaction term) $f$ is merely $C^1$ at $u=0$ due to a logarithmic competition term. We first derive the asymptotic behavior of (minimal speed)…

Analysis of PDEs · Mathematics 2020-09-03 Emeric Bouin , Christopher Henderson

We study the one-dimensional Fisher-KPP equation, with an initial condition $u_0(x)$ that coincides with the step function except on a compact set. A well-known result of M. Bramson states that, as $t\to+\infty$, the solution converges to a…

Analysis of PDEs · Mathematics 2018-04-19 James Nolen , Jean-Michel Roquejoffre , Lenya Ryzhik

We establish the logarithmic Bramson correction to the position of solutions to the Fisher--KPP equation with nonlocal diffusion. Solutions with step-like initial data typically resemble a front at position $c_{*} t - \frac{3}{2…

Analysis of PDEs · Mathematics 2020-05-13 Cole Graham

We study a variant of the Fisher-KPP equation with nonlocal dispersal. Using the theory of large deviations, we show the emergence of a "Bramson-like" logarithmic delay for the linearised equation with step-like initial data. We conclude…

Analysis of PDEs · Mathematics 2024-01-19 Nathanaël Boutillon

We investigate the influence of a general non-local advection term of the form K * u to propagation in the one-dimensional Fisher-KPP equation. This model is a generalization of the Keller-Segel-Fisher system. When K $\in$ L 1 (R), we…

Analysis of PDEs · Mathematics 2017-09-05 François Hamel , Christopher Henderson

Incorporating free boundary into time-delayed reaction-diffusion equations yields a compatible condition that guarantees the well-posedness of the initial value problem. With the KPP type nonlinearity we then establish a vanishing-spreading…

Analysis of PDEs · Mathematics 2021-08-03 Ningkui Sun , Jian Fang

We consider a certain lattice branching random walk with on-site competition and in an environment which is heterogeneous at a macroscopic scale $1/\varepsilon$ in space and time. This can be seen as a model for the spatial dynamics of a…

Probability · Mathematics 2024-12-24 Pascal Maillard , Gaël Raoul , Julie Tourniaire

We consider the Fisher-KPP equation with a non-local interaction term. We establish a condition on the interaction that allows for existence of non-constant periodic solutions, and prove uniform upper bounds for the solutions of the Cauchy…

Analysis of PDEs · Mathematics 2015-06-16 Francois Hamel , Lenya Ryzhik

We provide an asymptotic analysis of a non-local Fisher-KPP type equation in periodic media and with a non-local stable operator of order $\alpha$ $\in$ (0, 2). We perform a long time-long range scaling in order to prove that the stable…

Analysis of PDEs · Mathematics 2018-12-14 Alexis Léculier

We introduce a novel numerical method for direct simulation of front propagation in the Fisher-KPP equation with a time-dependent parameter on an infinite domain. The method computes a time-dependent boundary condition that accurately…

Fluid Dynamics · Physics 2026-02-12 Troy Tsubota , Smridhi Mahajan , Adrian van Kan , Edgar Knobloch

We investigate the super-linear spreading in a reaction-diffusion model analogous to the Fisher-KPP equation, but in which the population is heterogeneous with respect to the dispersal ability of individuals, and the saturation factor is…

Analysis of PDEs · Mathematics 2019-10-15 Vincent Calvez , Christopher Henderson , Sepideh Mirrahimi , Olga Turanova , Thierry Dumont

We consider here a model of accelerating fronts, introduced in [2], consisting of one equation with nonlocal diffusion on a line, coupled via the boundary condition with a reaction-diffusion equation of the Fisher-KPP type in the upper…

Analysis of PDEs · Mathematics 2019-11-11 Anne-Charline Chalmin , Jean-Michel Roquejoffre

We study propagation over $\mathbb{R}^d$ of the solution to a nonlocal nonlinear equation with anisotropic kernels, which can be interpretted as a doubly nonlocal reaction-diffusion equation of the Fisher--KPP-type. We prove that if the…

Analysis of PDEs · Mathematics 2018-04-30 Dmitri Finkelshtein , Yuri Kondratiev , Pasha Tkachov

This paper presents a novel way of computing front positions in Fisher-KPP equations. Our method is based on an exact relation between the Laplace transform of the initial condition and some integral functional of the front position. Using…

Statistical Mechanics · Physics 2018-06-13 Julien Berestycki , Éric Brunet , Bernard Derrida

We consider the solution $u(x,t)$ of the Fisher-KPP equation $\partial_t u=\partial_x^2u+u-u^2$ centred around its $\alpha$-level $\mu_t^{(\alpha)}$ defined as $u(\mu_t^{(\alpha)},t)=\alpha$. It is well known that for an initial datum that…

Analysis of PDEs · Mathematics 2016-03-22 Julien Berestycki , Éric Brunet

In this work, we consider a nonlocal Fisher-KPP reaction-diffusion problem with Neumann boundary condition and nonnegative initial data in a bounded domain in $\mathbb{R}^n (n \ge 1)$, with reaction term $u^\alpha(1-m(t))$, where $m(t)$ is…

Analysis of PDEs · Mathematics 2015-08-04 Shen Bian , Li Chen , Evangelos A. Latos

We consider the nonlocal KPP-Fisher equation $u_t(t,x) = u_{xx}(t,x) + u(t,x)(1-(K *u)(t,x))$ which describes the evolution of population density $u(t,x)$ with respect to time $t$ and location $x$. The non-locality is expressed in terms of…

Classical Analysis and ODEs · Mathematics 2016-02-09 Karel Hasik , Jana Kopfová , Petra Nábělková , Sergei Trofimchuk

We study nonlinear stability of pulled fronts in scalar parabolic equations on the real line of arbitrary order, under conceptual assumptions on existence and spectral stability of fronts. In this general setting, we establish sharp…

Analysis of PDEs · Mathematics 2020-12-07 Montie Avery , Arnd Scheel
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