Factorization of the reaction-diffusion equation, the wave equation, and other equations



We investigate equations of the form Dtu = Δu + ξ∇u for an unknown function u(t, x), t ∈ ℝ, xX, where Dtu = a0(u, t) + Σk=1rak(t, u)tku, Δ is the Laplace-Beltrami operator on a Riemannian manifold X, and ξ is a smooth vector field on X. More exactly, we study morphisms from this equation within the category PDE of partial differential equations, which was introduced by the author earlier. We restrict ourselves to morphisms of a special form—the so-called geometric morphisms, which are given by maps of X to other smooth manifolds (of the same or smaller dimension). It is shown that a map f: XY defines a morphism from the equation Dtu = Δu + ξ∇u if and only if, for some vector field Ξ and a metric on Y, the equality (Δ + ξ∇)f*v = f*(Δ + Ξ∇)v holds for any smooth function v: Y → ℝ. In this case, the quotient equation is Dtv = Δv + Ξ∇v for an unknown function v(t, y), yY. It is also shown that, if a map f: XY is a locally trivial bundle, then f defines a morphism from the equation Dtu = Δu if and only if fibers of f are parallel and, for any path γ on Y, the expansion factor of a fiber translated along the horizontal lift γ to X depends on γ only.


category of partial differential equations reaction-diffusion equation heat equation wave equation. 


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  1. 1.
    M. F. Prokhorova, Factorization of Partial Differential Equations: Structure of the Parabolic Equations Category, Preprint No. 10/2005 (St. Petersburg Dep. Steklov Inst. Math., Russ. Acad. Sci., 2005) [in Russian].Google Scholar
  2. 2.
    M. F. Prokhorova, Modeling of the Heat Equation and Stefan Problem (IMM UrO RAN, Yekaterinburg, 2000), Available from VINITI, No. 347-V00 [in Russian].Google Scholar
  3. 3.
    M. F. Prokhorova, “The structure of the category of parabolic equations,” http://arxiv.org/pdf/math/0512094v5.pdf, Submitted May 29, 2009.
  4. 4.
    P. Olver, Applications of Lie Groups to Differential Equations (Springer, New York, 1986).CrossRefMATHGoogle Scholar
  5. 5.
    A. M. Vinogradov, “Geometry of nonlinear differential equations,” in Results in Science and Technology (VINITI, Moscow, 1980), Ser. Geometry Problems, Vol. 11, pp. 89–134 [in Russian].Google Scholar
  6. 6.
    A. M. Vinogradov, “Category of nonlinear differential equations,” in Global Analysis. Studies and Applications I, Ed. by Yu. G. Borisovich and Yu. E. Gliklikh (Springer, Berlin, 1984), Ser. Lecture Notes in Mathematics, Vol. 1108, pp. 77–102.CrossRefGoogle Scholar
  7. 7.
    A. V. Bocharov, A. M. Verbovetskii, A. M. Vinogradov, et al., Symmetries and Conservation Laws for Differential Equations of Mathematical Physics (Amer. Math. Soc., Providence, RI, 1999).Google Scholar
  8. 8.
    M. Hirsch, Differential Topology (Springer, New York, 1976).CrossRefMATHGoogle Scholar
  9. 9.
    F. Warner, Foundations of Differentiable Manifolds and Lie Groups (Springer, New York, 1971).MATHGoogle Scholar

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© Pleiades Publishing, Ltd. 2014

Authors and Affiliations

  1. 1.Institute of Mathematics and MechanicsUral Branch of the Russian Academy of SciencesYekaterinburgRussia
  2. 2.Institute of Mathematics and Computer ScienceUral Federal UniversityYekaterinburgRussia

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