Nonlinearly determined wavefronts of the Nicholson's diffusive equation: when small delays are not harmless

Abstract

By proving the existence of non-monotone and non-oscillating wavefronts for the Nicholson's blowflies diffusive equation (the NDE), we answer an open question raised in [16]. Surprisingly, these wavefronts can be observed only for sufficiently small delays. Similarly to the pushed fronts, obtained waves are not linearly determined. In contrast, a broader family of eventually monotone wavefronts for the NDE is indeed determined by properties of the spectra of the linearized equations. Our proofs use essentially several specific characteristics of the blowflies birth function (its unimodal form and the negativity of its Schwarz derivative, among others). One of the key auxiliary results of the paper shows that the Mallet-Paret--Cao--Arino theory of super-exponential solutions for scalar equations can be extended for some classes of second order delay differential equations. For the new type of non-monotone waves to the NDE, our numerical simulations also confirm their stability properties established by Mei et al.

arXiv comment22 pages, 4 figure, submitted

References in corpus (8)

• Non-monotone travelling waves in a single species reaction-diffusion equation with delay
• On uniqueness of semi-wavefronts (Diekmann-Kaper theory of a nonlinear convolution equation re-visited)
• Global continuation of monotone wavefronts
• Stability of traveling wavefronts in discrete reaction-diffusion equations with nonlocal delay effects
• Positive travelling fronts for reaction-diffusion systems with distributed delay
• Monotone waves for non-monotone and non-local monostable reaction-diffusion equations
• A note on the existence of non-monotone non-oscillating wavefronts
• Existence and uniqueness of monotone wavefronts in a nonlocal resource-limited model