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Hopf dances near the tips of Busse balloons. (English) Zbl 1252.35032

This paper deals with stationary periodic patterns related with reaction-diffusion systems, in one spatial dimension, of the form \[ \left\{\begin{aligned} \epsilon^2U_t&=U_{xx}-\epsilon^2\mu U+U^{\alpha_1}V^{\beta_1},\\ V_t&=\epsilon^2V_{xx}-V+U^{\alpha_2}V^{\beta_2}, \end{aligned}\right.\tag{1} \] with \(0<\epsilon\ll1\), \(\mu>0\), \(\alpha_2<0\), \(\beta_1>1\), \(\beta_2>1\), \(d=(\alpha_1-1)(\beta_2-1)-\alpha_2\beta_1>0\), known as the generalized Gierer-Meinhardt model.The associated Busse balloon is the region, in the wave number-parameter space, for which stable periodic patterns exist. The Hopf dance, near the tip of the Busse balloon is, first, graphically presented in the case of the Gray-Scott model (Sections 2–3). The results are generalized to system (1) in Sections 4–5. In the last section, possible extensions to larger classes of systems are discussed.

MSC:

35B25 Singular perturbations in context of PDEs
35K57 Reaction-diffusion equations
37L15 Stability problems for infinite-dimensional dissipative dynamical systems
34L16 Numerical approximation of eigenvalues and of other parts of the spectrum of ordinary differential operators
35B36 Pattern formations in context of PDEs
35K45 Initial value problems for second-order parabolic systems
35K58 Semilinear parabolic equations