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We give sufficient conditions for the existence of positive travelling wave solutions for multi-dimensional autonomous reaction-diffusion systems with distributed delay. To prove the existence of travelling waves, we give an abstract…

Classical Analysis and ODEs · Mathematics 2015-03-17 Teresa Faria , Sergei Trofimchuk

In this work, we construct a transformation between the solutions to the following reaction-convection-diffusion equation $$ \partial_t u=(u^m)_{xx}+a(x)(u^m)_x+b(x)u^m, $$ posed for $x\in\real$, $t\geq0$ and $m>1$, where $a$, $b$ are two…

We consider a family of exact solutions to a nonlinear reaction-diffusion model, constructed using nonclassical symmetry analysis. In a particular limit, the mathematical model approaches the well-known Fisher-KPP model, which means that it…

Exactly Solvable and Integrable Systems · Physics 2022-02-21 Scott W McCue , Bronwyn H Bradshaw-Hajek , Matthew J Simpson

A new self-similar solution describing the dynamical condensation of a radiative gas is investigated under a plane-parallel geometry. The dynamical condensation is caused by thermal instability. The solution is applicable to generic flow…

Astrophysics · Physics 2009-11-13 Kazunari Iwasaki , Toru Tsuribe

Assume that $N_m(x)$ denotes the density of the population at a point $x$ at the beginning of the reproductive season in the $m$th year. We study the following impulsive reaction-diffusion model for any $m\in \mathbb Z^+$…

Analysis of PDEs · Mathematics 2016-11-18 Mostafa Fazly , Mark Lewis , Hao Wang

We calculate the probability distribution function (PDF) of an overdamped Brownian particle moving in a periodic potential energy landscape $U(x)$. The PDF is found by solving the corresponding Smoluchowski diffusion equation. We derive the…

Statistical Mechanics · Physics 2018-11-21 Matan Sivan , Oded Farago

The replication and differentiation of spots in reaction diffusion equations are studied by extending the Gray-Scott model with self-replicating spots to include many degrees of freedom needed to model systems with many chemicals. By…

Pattern Formation and Solitons · Physics 2009-11-07 Hiroaki Takagi , Kunihiko Kaneko

The most general nonuniform reaction-diffusion models on a one-dimensional lattice with boundaries, for which the time evolution equations of corre- lation functions are closed, are considered. A transfer matrix method is used to find the…

Statistical Mechanics · Physics 2010-04-09 Amir Aghamohammadi , Mohammad Khorrami

We study the behavior of solutions of a monostable reaction-diffusion equation $u_t=\Delta_x u +u_{yy} +f(u)$ ($x \in \mathbb{R}^{n-1}$, $y \in \mathbb{R}$, $t>0$), with the unstable equilibrium point $0$ and the stable equilibrium point…

Analysis of PDEs · Mathematics 2026-02-11 Ryo Kiyono

The nonlocal Fisher equation is a diffusion-reaction equation with a nonlocal quadratic competition, which describes the reaction between distant individuals. This equation arises in evolutionary biological systems, where the arena for the…

Pattern Formation and Solitons · Physics 2018-04-25 Yehuda A. Ganan , David A. Kessler

The use of reaction-diffusion models rests on the key assumption that the underlying diffusive process is Gaussian. However, a growing number of studies have pointed out the prevalence of anomalous diffusion, and there is a need to…

Pattern Formation and Solitons · Physics 2009-11-07 D. del-Castillo-Negrete , B. A. Carreras , V. E. Lynch

We present a dark fluid model described as a non-viscous, non-relativistic, rotating, and self-gravitating fluid. We assumed that the system has spherical symmetry and the matter can be described with the polytropic equation of state. The…

Fluid Dynamics · Physics 2026-03-11 Balázs Endre Szigeti , Imre Ferenc Barna , Gergely Gábor Barnaföldi

We consider the explicit solution to the axisymmetric diffusion equation. We recast the solution in the form of a Mellin inversion formula, and outline a method to compute a formula for $u(r,t)$ as a series using the Cauchy residue theorem.…

Classical Analysis and ODEs · Mathematics 2021-10-07 Alexander E Patkowski

Reaction-diffusion equations (RDEs) model the spatiotemporal evolution of a density field $u(\vec{x},t)$ according to diffusion and net local changes. Usually, the diffusivity is positive for all values of $u,$ which causes the density to…

We prove the existence of a family of travelling wave solutions in a variant of the $\textit{Zeldovich-Frank-Kamenetskii (ZFK) equation}$, a reaction-diffusion equation which models the propagation of planar laminar premixed flames in…

Dynamical Systems · Mathematics 2024-11-21 Samuel Jelbart , Kristian Uldall Kristiansen , Peter Szmolyan

We prove the existence of a continuous family of positive and generally non-monotone travelling fronts in delayed reaction-diffusion equations $u_t(t,x) = \Delta u(t,x)- u(t,x) + g(u(t-h,x)) (*)$, when $g \in C^2(R_+,R_+)$ has exactly two…

Dynamical Systems · Mathematics 2013-03-04 Teresa Faria , Sergei Trofimchuk

The Fisher and Burgers' equations with finite memory transport, describing reaction-diffusion and convection-diffusion processes, respectively have recently attracted a lot of attention in the context of chemical kinetics, mathematical…

Pattern Formation and Solitons · Physics 2007-05-23 Sandip Kar , Suman Kumar Banik , Deb Shankar Ray

The problem of front propagation in flowing media is addressed for laminar velocity fields in two dimensions. Three representative cases are discussed: stationary cellular flow, stationary shear flow, and percolating flow. Production terms…

Chaotic Dynamics · Physics 2009-10-31 M. Abel , A. Celani , D. Vergni , A. Vulpiani

We study the Dirichlet problem for the non-local diffusion equation $u_t=\int\{u(x+z,t)-u(x,t)\}\dmu(z)$, where $\mu$ is a $L^1$ function and $``u=\phi$ on $\partial\Omega\times(0,\infty)$'' has to be understood in a non-classical sense. We…

Analysis of PDEs · Mathematics 2007-06-13 Emmanuel Chasseigne

We describe a general Godunov type splitting for numerical simulations of the Fisher/Kolmogorov-Petrovski-Piskunov growth and diffusion equation in two spatial dimensions. In particular, the method is appropriate for modeling population…

Numerical Analysis · Mathematics 2015-02-17 W. P. Petersen , S. Callegari , N. Tkachenko , J. D. Weissmann , Ch. P. E. Zollikofer