We consider a branching-selection system in R with N particles which give birth independently at rate 1 and where after each birth the leftmost particle is erased, keeping the number of particles constant. We show that, as N → ∞, the empirical measure process associated to the system converges in distribution to a deterministic measure-valued process whose densities solve a free boundary integr...

Parametric excitation of autoresonant solutions of the nonlinear Schrodinger (NLS) equation by a chirped frequency traveling wave is discussed. Fully nonlinear theory of the process is developed based on Whitham's averaged variational principle and its predictions verified in numerical simulations. The weakly nonlinear limit of the theory is used to find the threshold on the amplitude of the dr...

The dynamics of a gravity-driven thin film flow with insoluble surfactant are described in the lubrication approximation by a coupled system of nonlinear PDEs. When the total quantity of surfactant is fixed, a traveling wave solution exists. For the case of constant flux of surfactant from an upstream reservoir, global traveling waves no longer exist as the surfactant accumulates at the leading...

Vaccination has been included in a model which describes an epidemic. A traveling wave solution together with an equilibrium and stability analysis have been done to the model.

In the paper, a auxiliary equation expansion method and its a lgorithm is proposed by studying a second order nonlinear ordinary differential equation with a six-degree term.The method is applied to the generalized derivative Schrödinger equation .As a result,some new exact traveling wave solution are obtained which singular solutions,triangular periodic wave solution and Jacobian elliptic func...

Abstract. Using the method of sub-super-solution, we construct a solution of (−∆)su − cuz − f(u) = 0 on R of pyramidal shape. Here (−∆)s is the fractional Laplacian of sub-critical order 1/2 < s < 1 and f is a bistable nonlinearity. Hence, the existence of a traveling wave solution for the parabolic fractional Allen-Cahn equation with pyramidal front is asserted. The maximum of planar traveling...

We consider traveling wave phenomena for a viscoelastic generalization of Burgers’ equation. For asymptotically constant velocity profiles we find three classes of solutions corresponding to smooth traveling waves, piecewise smooth waves, and piecewise constant (shock) solutions. Each solution type is possible for a given pair of asymptotic limits, and we characterize the dynamics in terms of t...

A nonlinear streamwise traveling-wave solution is obtained by homotopy for square duct flow. For a particular symmetry of the perturbations, this wave comes into existence at about Re(b)=600 (based on half-duct width and bulk speed) for a streamwise wave number alpha=0.85 . The resulting four-vortex mean flow resembles the transitional flow structures observed in previous simulations.

We investigate the qualitative behavior of solutions of a Burgers-Boussinesq system – a reaction-diffusion equation coupled via gravity to a Burgers equation – by a combination of numerical, asymptotic and mathematical techniques. Numerical simulations suggest that when the gravity ρ is small the solutions decompose into a traveling wave and an accelerated shock wave moving in opposite directio...

Recent biological research has sought to understand how biochemical signaling pathways, such as the mitogen-activated protein kinase (MAPK) family, influence the migration of a population of cells during wound healing. Fisher’s Equation has been used extensively to model experimental wound healing assays due to its simple nature and known traveling wave solutions. This partial differential equa...