Abstract
We analyze the transition between pulled and pushed fronts both analytically and numerically from a model-independent perspective. Based on minimal conceptual assumptions, we show that pushed fronts bifurcate from a branch of pulled fronts with an effective speed correction that scales quadratically in the bifurcation parameter. Strikingly, we find that in this general context without assumptions on comparison principles, the pulled front loses stability and gives way to a pushed front when monotonicity in the leading edge is lost. Our methods rely on far-field core decompositions that identify explicitly asymptotics in the leading edge of the front. We show how the theoretical construction can be directly implemented to yield effective algorithms that determine spreading speeds and bifurcation points with exponentially small error in the domain size. Example applications considered here include an extended Fisher-KPP equation, a Fisher–Burgers equation, negative taxis in combination with logistic population growth, an autocatalytic reaction, and a Lotka-Volterra model.










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Data Availability
Matlab code to perform continuation for scalar PDEs is available at GitHub/mholzergmu/scalar-pushed-pulled-continuation. The datasets generated during and analyzed during the current study are available from the corresponding author (msavery@umn.edu) on reasonable request.
Notes
The terminology “simple double root” is motivated by the fact that \((0,\nu _0)\) is “simple” in a degree counting sense as a solution to the double root equation \(d=\partial _\nu d=0\) assuming that \(\partial _{\nu \nu }d,\partial _\lambda d\ne 0\).
References
Alhasanat, A., Ou, C.: Minimal-speed selection of traveling waves to the Lotka–Volterra competition model. J. Differ. Equ. 266(11), 7357–7378 (2019a)
Alhasanat, A., Ou, C.: On a conjecture raised by Yuzo Hosono. J. Dynam. Differ. Equ. 31(1), 287–304 (2019b)
An, J., Henderson, C., Ryzhik, L.: Pushed, pulled and pushmi-pullyu fronts of the Burgers-FKPP equation. J. Eur. Math. Soc. (JEMS) (to appear)
Avery, M.: Front selection in reaction–diffusion equations via diffusive normal forms. Preprint (2022)
Avery, M., Garénaux, L.: Spectral stability of the critical front in the extended Fisher-KPP equation. Z. Angew. Math. Phys. 74, 71 (2023)
Avery, M., Scheel, A.: Universal selection of pulled fronts. Commun. Am. Math. Soc. 2, 172–231 (2022)
Avery, M., Dedina, C., Smith, A., Scheel, A.: Instability in large bounded domains–branched versus unbranched resonances. Nonlinearity 34(11), 7916–7937 (2021)
Benguria, R., Depassier, M.: Variational characterization of the speed of propagation of fronts for the nonlinear diffusion equation. Commun. Math. Phys. 175, 221–227 (1996)
Bers, A., Rosenbluth, M., Sagdeev, R.: Handbook of plasma physics. MN Rosenbluth and RZ Sagdeev eds, 1(3.2) (1983)
Beyn, W.-J.: The numerical computation of connecting orbits in dynamical systems. IMA J. Numer. Anal. 10(3), 379–405 (1990)
Beyn, W.-J., Thümmler, V.: Freezing solutions of equivariant evolution equations. SIAM J. Appl. Dyn. Syst. 3(2), 85–116 (2004)
Bramson, M.: Maximal displacement of branching Brownian motion. Commun. Pure Appl. Math. 31(5), 531–581 (1978)
Bramson, M.: Convergence of solutions of the Kolmogorov equation to traveling waves. Mem. Am. Math. Soc. (1983)
Champneys, A.R., Kuznetsov, Y.A., Sandstede, B.: A numerical toolbox for homoclinic bifurcation analysis. Int. J. Bifur. Chaos Appl. Sci. Eng. 6(5), 867–887 (1996)
Chen, K., Deiman, Z., Goh, R., Jankovic, S., Scheel, A.: Strain and defects in oblique stripe growth. Multiscale Model. Simul. 19(3), 1236–1260 (2021)
Collet, P., Eckmann, J.-P.: Instabilities and Fronts in Extended Systems. Princeton Series in Physics, Princeton University Press, Princeton, NJ (1990)
Ebert, U., van Saarloos, W.: Front propagation into unstable states: universal algebraic convergence towards uniformly translating pulled fronts. Phys. D 146, 1–99 (2000)
Faye, G., Holzer, M., Scheel, A.: Linear spreading speeds from nonlinear resonant interaction. Nonlinearity 30(6), 2403–2442 (2017)
Faye, G., Holzer, M., Scheel, A., Siemer, L.: Invasion into remnant instability: a case study of front dynamics. Indiana Univ. Math. J. 71, 1819–1896 (2022)
Focant, S., Gallay, T.: Existence and stability of propagating fronts for an autocatalytic reaction-diffusion system. Phys. D 120(3–4), 346–368 (1998)
Gohberg, I., Lancaster, P., Rodman, L.: Invariant Subspaces of Matrices with Applications. SIAM (2006)
Hadeler, K.-P., Rothe, F.: Traveling fronts in nonlinear diffusion equations. J. Math. Biol. 2(1), 251–263 (1975)
Hamel, F., Nolen, J., Roquejoffre, J.-M., Ryzhik, L.: A short proof of the logarithmic Bramson correction in Fisher-KPP equations. Netw. Heterog. Media 8(1), 275–289 (2013)
Henderson, C.: Slow and fast minimal speed traveling waves of the FKPP equation with chemotaxis. J. Math. Pures. Appl. 167, 175–203 (2022)
Holzer, M.: Anomalous spreading in a system of coupled Fisher-KPP equations. Phys. D 270, 1–10 (2014)
Holzer, M., Scheel, A.: A slow pushed front in a Lotka–Volterra competition model. Nonlinearity 25(7), 2151–2179 (2012)
Holzer, M., Scheel, A.: Criteria for pointwise growth and their role in invasion processes. J. Nonlinear Sci. 24(1), 661–709 (2014)
Hosono, Y.: The minimal speed of traveling fronts for a diffusive Lotka–Volterra competition model. Bull. Math. Biol. 60(3), 435–448 (1998)
Huang, W.: Problem on minimum wave speed for a Lotka–Volterra reaction–diffusion competition model. J. Dynam. Differ. Equ. 22(2), 285–297 (2010)
Kolmogorov, A., Petrovskii, I., Piskunov, N.: Etude de l’equation de la diffusion avec croissance de la quantite de matiere et son application a un probleme biologique. Bjul. Moskowskogo Gos. Univ. Ser. Internat. Sect. A 1, 1–26 (1937)
Lau, K.-S.: On the nonlinear diffusion equation of Kolmogorov, Petrovsky, and Piscounov. J. Differ. Equ. 59(1), 44–70 (1985)
Lewis, M.A., Li, B., Weinberger, H.F.: Spreading speed and linear determinacy for two-species competition models. J. Math. Biol. 45(3), 219–233 (2002)
Lloyd, D.J.B., Scheel, A.: Continuation and bifurcation of grain boundaries in the Swift–Hohenberg equation. SIAM J. Appl. Dyn. Syst. 16(1), 252–293 (2017)
Lord, G.J., Peterhof, D., Sandstede, B., Scheel, A.: Numerical computation of solitary waves in infinite cylindrical domains. SIAM J. Numer. Anal. 37(5), 1420–1454 (2000)
Pogan, A., Scheel, A.: Instability of spikes in the presence of conservation laws. Z. Angew. Math. Phys. 61(6), 979–998 (2010)
Sandstede, B., Scheel, A.: Absolute and convective instabilities of waves on unbounded and large bounded domains. Phys. D 145(3), 233–277 (2000)
Sandstede, B., Scheel, A.: On the structure of spectra of modulated travelling waves. Math. Nachr. 232, 39–93 (2001)
Sandstede, B., Scheel, A.: Defects in oscillatory media: toward a classification. SIAM J. Appl. Dyn. Syst. 3(1), 1–68 (2004)
Sandstede, B., Scheel, A.: Relative Morse indices, Fredholm indices, and group velocities. Discrete Contin. Dyn. Syst. 20(1), 139–158 (2008)
Sattinger, D.: Weighted norms for the stability of traveling waves. J. Differe. Equ. 25(1), 130–144 (1977)
Stegemerten, F., Gurevich, S.V., Thiele, U.: Bifurcations of front motion in passive and active Allen-Cahn-type equations. Chaos 30(5), 053136, 12 (2020)
van Saarloos, W.: Front propagation into unstable states. Phys. Rep. 386, 29–222 (2003)
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The material here is based on work supported by the National Science Foundation, through through the GRFP-00074041 (MA), NSF-DMS-2202714 (MA), NSF-DMS-2007759 (MH) and NSF-DMS-1907391 (AS). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation. The authors have no other competing interests that are relevant to the content of this article.
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Avery, M., Holzer, M. & Scheel, A. Pushed-to-Pulled Front Transitions: Continuation, Speed Scalings, and Hidden Monotonicty. J Nonlinear Sci 33, 102 (2023). https://doi.org/10.1007/s00332-023-09957-3
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DOI: https://doi.org/10.1007/s00332-023-09957-3