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Perturbative Expansions, Convergence of

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Mathematics of Complexity and Dynamical Systems

Article Outline

Glossary

Definition of the Subject

Introduction

Poincaré–Dulac Normal Forms

Convergence and Convergence Problems

Lie Algebra Arguments

NFIM and Sets of Analyticity

Hamiltonian Systems

Future Directions

Bibliography

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Abbreviations

Resonant eigenvalues:

Let B be a linear endomorphism of \({\mathbb{C}^n}\), with eigenvalues \({\lambda_1,\dots, \lambda_n}\) (counted according to multiplicity). One calls these eigenvalues resonant if there are integers \({d_j\geq 0}\), \({\sum d_j\geq 2}\), and some \({k\in\{1,\dots,n\}}\) such that

$$ d_1\lambda_1+\dots+d_n\lambda_n-\lambda_k=0\:. $$

If B is represented by a matrix in Jordan canonical then the associated vector monomial \({x_1^{d_1}\dots x_n^{d_n} e_k}\) will be called a  resonant monomial . (Here \({e_1,\dots,e_n}\) denote the standard basis, and the x i are the corresponding coordinates.)

Poincaré–Dulac normal form :

Let \({f=B+\dots}\) be a formal or analytic vector field about 0, and let \({B_\mathrm{s}}\) be the semisimple part of B. Then one says that f is in Poincaré–Dulac normal form (PDNF) if \({[B_\mathrm{s}, f]=0}\). An equivalent characterization, if B is in Jordan form, is to say that only resonant monomials occur in the series expansion.

Normalizing transformations and convergence:

A relatively straightforward argument shows that any formal vector field \({f=B+\dots}\) can be transformed to a formal vector field in PDNF via a formal power series transformation. But for analytic vector fields, the existence of a convergent transformation is not assured. There are two obstacles to convergence: First, the possible existence of small denominators (roughly, this means that the eigenvalues satisfy “near‐resonance conditions”); and second, “algebraic” obstructions due to the particular form of the normalized vector field.

Lie algebras of vector fields:

The vector space of analytic vector fields on an open subset U of \({{\mathbb C}^n}\), with the bracket \({[p, q]}\) defined by

$$ [p, q](x):=Dq(x)\,p(x) - Dp(x)\,q(x) $$

becomes a Lie algebra , as is well known. Mutatis mutandis, this also holds for local analytic and for formal vector fields. As noted previously, PDNF is most naturally defined via this Lie bracket. Moreover, the “algebraic” obstructions to convergence are most appropriately discussed within the Lie algebra framework.

Normal form on invariant manifolds:

While there may not exist a convergent transformation to PDNF for a given vector field f, one may have a convergent transformation to a “partially normalized” vector field, which admits a certain invariant manifold and is in PDNF when restricted to this manifold. This observation is of some practical importance.

Bibliography

  1. Arnold VI (1982) Geometrical methods in the theory of ordinary differential equations. Springer, Berlin

    Google Scholar 

  2. Arnold VI, Kozlov VV, Neishtadt AI (1993) Mathematical aspects of classical and celestial mechanics. In: Arnold VI (ed) Dynamical Systems III, Encyclop Math Sci, vol 3, 2nd edn. Springer, New York

    Google Scholar 

  3. Bambusi D, Cicogna G, Gaeta G, Marmo G (1998) Normal forms, symmetry and linearization of dynamical systems. J Phys A 31:5065–5082

    Article  MathSciNet  MATH  Google Scholar 

  4. Bibikov YN (1979) Local theory of nonlinear analytic ordinary differential equations. Lecture Notes in Math 702. Springer, New York

    Google Scholar 

  5. Birkhoff GD (1927) Dynamical systems, vol IX. American Mathematical Society, Colloquium Publications, Providence, RI

    Google Scholar 

  6. Bruno AD (1971) Analytical form of differential equations. Trans Mosc Math Soc 25:131–288

    Google Scholar 

  7. Bruno AD (1989) Local methods in nonlinear differential equations. Springer, New York

    Book  MATH  Google Scholar 

  8. Bruno AD, Edneral VF (2006) The normal form and the integrability of systems of ordinary differential equations. (Russian) Programmirovanie 3:22–29; translation in Program Comput Software 32(3):139–144

    Google Scholar 

  9. Bruno AD, Walcher S (1994) Symmetries and convergence of normalizing transformations. J Math Anal Appl 183:571–576

    Article  MathSciNet  MATH  Google Scholar 

  10. Chow S-N, Li C, Wang D (1994) Normal forms and bifurcations of planar vector fields. Cambridge Univ Press, Cambridge

    Book  Google Scholar 

  11. Cicogna G (1996) On the convergence of normalizing transformations in the presence of symmetries. J Math Anal Appl 199:243–255

    Article  MathSciNet  MATH  Google Scholar 

  12. Cicogna G (1997) Convergent normal forms of symmetric dynamical systems. J Phys A 30:6021–6028

    Article  MathSciNet  MATH  Google Scholar 

  13. Cicogna G, Gaeta G (1999) Symmetry and perturbation theory. In: Nonlinear Dynamics, Lecture Notes in Phys 57. Springer, New York

    Google Scholar 

  14. Cicogna G, Walcher S (2002) Convergence of normal form transformations: The role of symmetries. Acta Appl Math 70:95–111

    Article  MathSciNet  MATH  Google Scholar 

  15. Cushman R, Sanders JA (1990) A survey of invariant theory applied to normal forms of vectorfields with nilpotent linear part, IMA vol Math Appl 19. Springer, New York, pp 82–106

    Google Scholar 

  16. DeLatte D, Gramchev T (2002) Biholomorphic maps with linear parts having Jordan blocks: linearization and resonance type phenomena. Math Phys Electron J 8(2):27 (electronic)

    MathSciNet  Google Scholar 

  17. Dulac H (1912) Solutions d'un systéme d'équations différentielles dans le voisinage de valeurs singuliéres. Bull Soc Math Fr 40:324–383

    MathSciNet  MATH  Google Scholar 

  18. Ecalle J (1981) Sur les fonctions résurgentes I. Publ Math d'Orsay 81(5):1–247

    Google Scholar 

  19. Ecalle J (1981) Sur les fonctions résurgentes II. Publ Math d'Orsay 81(6):248–531

    Google Scholar 

  20. Edneral VF (2005) Looking for periodic solutions of ODE systems by the normal form method. In: Differential equations with symbolic computation. Trends Math, Birkhäuser, Basel, pp 173–200

    Chapter  Google Scholar 

  21. Gramchev T (2002) On the linearization of holomorphic vector fields in the Siegel domain with linear parts having nontrivial Jordan blocks SPT. In: Symmetry and perturbation theory (Cala Gonone). World Sci Publ, River Edge, NJ, pp 106–115

    Google Scholar 

  22. Gramchev T, Tolis E (2006) Solvability of systems of singular partial differential equations in function spaces. Integral Transforms Spec Funct 17:231–237

    Article  MathSciNet  MATH  Google Scholar 

  23. Gramchev T, Walcher S (2005) Normal forms of maps: Formal and algebraic aspects. Acta Appl Math 87(1–3):123–146

    Article  MathSciNet  MATH  Google Scholar 

  24. Gramchev T, Yoshino M (1999) Rapidly convergent iteration method for simultaneous normal forms of commuting maps. Math Z 231:745–770

    Article  MathSciNet  MATH  Google Scholar 

  25. Iooss G, Adelmeyer M (1992) Topics in Bifurcation Theory and Applications. World Scientific, Singapore

    MATH  Google Scholar 

  26. Ito H (1989) Convergence of Birkhoff normal forms for integrable systems. Comment Math Helv 64:412–461

    Article  MathSciNet  MATH  Google Scholar 

  27. Ito H (1992) Integrability of Hamiltonian systems and Birkhoff normal forms in the simple resonance case. Math Ann 292:411–444

    Article  MathSciNet  MATH  Google Scholar 

  28. Kappeler T, Kodama Y, Nemethi A (1998) On the Birkhoff normal form of a completely integrable system near a fixed point in resonance. Ann Scuola Norm Sup Pisa Cl Sci 26:623–661

    MathSciNet  MATH  Google Scholar 

  29. Markhashov LM (1974) On the reduction of an analytic system of differential equations to the normal form by an analytic transformation. J Appl Math Mech 38:788–790

    MathSciNet  Google Scholar 

  30. Martinet J, Ramis J-P (1983) Classification analytique des équations différentielles non linéaires résonnantes du premier ordre. Ann Sci Ecole Norm Sup 16:571–621

    MathSciNet  MATH  Google Scholar 

  31. Perez Marco R (1995) Nonlinearizable holomorphic dynamics having an uncountable number of symmetries. Invent Math 119:67–127

    Article  MathSciNet  MATH  Google Scholar 

  32. Perez–Marco R (1997) Fixed points and circle maps. Acta Math 179:243–294

    Google Scholar 

  33. Perez–Marco R (2003) Convergence and generic divergence of the Birkhoff normal form. Ann Math 157:557–574

    Google Scholar 

  34. Pliss VA (1965) On the reduction of an analytic system of differential equations to linear form. Differ Equ 1:153–161

    MathSciNet  Google Scholar 

  35. Poincaré H (1879) Sur les propriétés des fonctions deéfinies par les équations aux differences partielles. These, Paris

    Google Scholar 

  36. Sanders JA (2003) Normal form theory and spectral sequences. J Differential Equations 192:536–552

    Article  MathSciNet  MATH  Google Scholar 

  37. Sanders JA (2005) Normal form in filtered Lie algebra representations. Acta Appl Math 87:165–189

    Article  MathSciNet  MATH  Google Scholar 

  38. Siegel CL (1952) Über die Normalform analytischer Differentialgleichungen in der Nähe einer Gleichgewichtslösung. Nachr Akad Wiss Göttingen, Math-Phys Kl, pp 21–30

    Google Scholar 

  39. Stolovitch L (2000) Singular complete integrability. IHES Publ Math 91:133–210

    MathSciNet  MATH  Google Scholar 

  40. Vey J (1979) Algébres commutatives de champs de vecteurs isochores. Bull Soc Math France 107(4):423–432

    MathSciNet  MATH  Google Scholar 

  41. Verhulst F (2005) Methods and applications of singular perturbations Boundary layers and multiple timescale dynamics. In: Texts in Applied Mathematics, vol 50. Springer, New York

    Google Scholar 

  42. Voronin SM (1981) Analytic classification of germs of conformal mappings \({(\mathbb{C},0)\rightarrow(\mathbb{C},0)}\). Funct Anal Appl 15:1–13

    Article  MathSciNet  MATH  Google Scholar 

  43. Walcher S (1991) On differential equations in normal form. Math Ann 291:293–314

    Article  MathSciNet  MATH  Google Scholar 

  44. Walcher S (1993) On transformations into normal form. J Math Anal Appl 180(2):617–632

    Article  MathSciNet  MATH  Google Scholar 

  45. Walcher S (2000) On convergent normal form transformations in presence of symmetries. J Math Anal Appl 244:17–26

    Article  MathSciNet  MATH  Google Scholar 

  46. Zung NT (2002) Convergence versus integrability in Poincaré–Dulac normal form. Math Res Lett 9(2–3):217–228

    MathSciNet  MATH  Google Scholar 

  47. Zung NT (2005) Convergence versus integrability in Birkhoff normal form. Ann Math (2) 161(1):141–156

    Article  MathSciNet  Google Scholar 

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Walcher, S. (2012). Perturbative Expansions, Convergence of. In: Meyers, R. (eds) Mathematics of Complexity and Dynamical Systems. Springer, New York, NY. https://doi.org/10.1007/978-1-4614-1806-1_87

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