Program of the 2nd year of Master for 2005-2006 :
 
Solitons and Integrable Systems
 
V.B. Matveev, M. A. Semenov-Tian-Shansky


***********************************************************************************************************************

The theory of integrable systems represents a real breakthrough in the development of mathematics at the end of the 20th century. After the striking discovery, by Gardner, Green, Kruskal and Miura, of an unexpected link between the Korteweg - de Vries equation in non-linear hydrodynamics and Scattering Theory in Quantum Mechanics, the new approach to the study of partial differential equations, called CISM (Classical Inverse Scattering Method), enjoyed a rapid expansion and allowed to discover new and unexpected connections between different branches of mathematics. The theory of integrable systems found various applications in physics, ranging from hydrodynamics and non-linear optics to astrophysics and elementary particle theory. In the last decades it has also brought about many importantant discoveries in pure mathematics, such as a solution of Schottki problem in algebraic geometry, the creation of quantum group theory, the discovery of new knot invariants, or Donaldson's theory in the low dimensional differential topology. In its modern version, the theory of integrable system reunites powerful analytic methods (Riemann-Hilbert problem, Riemann's theta functions) with the algebraic methods of Lie theory (especially in infinite dimension).

The program for the second year of the Master "Mathématiques Approfondies" at Burgundy University, for the academic year 2005-2006, is conceived as a solid introduction to the theory of integrable systems which will allow students not only to learn the basic elements in the field but also to be able to tackle open problems. The program might be modified according to the mathematical background of the students attending the course.
During the first semester a certain amount of time will be devoted to revisions of the basic concepts needed. The first term will consist of three courses:

I- Révisions et compléments d'Analyse (revision and complements of analysis) (30 hours and 6 CE)
II- Révisions et compléments de Mathématiques Générales (revision and complements of general mathematics)(30 hours and 6 CE).
III- Compléments de théorie des fonctions analytiques (Advanced topics of the theory of analytic functions) (V.B. Matveev, 20 hours and 8 CE).

 
***********************************************************************************************************************

The program of the course

Advanced topics of the theory of analytic functions

will  acquaint the students with the analytic tools necessary for the second part of the MMA2 and, at the same time, will be useful to prepare the "agrégation" exam. The program will include:

 Infinite products and the Weierstrass theorem. Entire functions ;  meromorphic functions and the Mittag-Leffler theorem.
 Riemann surfaces and analytic multi-valued functions.
 Conformal maps.
 Asymptotical methods: Laplace's method, stationary phase method, saddle point method.
 Linear differential equations with rational coefficients in the complex plane.
 Special functions I: Euler’s Gamma function; Stirling's formula.
 Airy's function.
 Theta functions and elliptic functions.
 Cauchy integral and the Riemann-Hilbert problem I.

 
***********************************************************************************************************************

The course
« Solitons and Integrable System » for the second semester will be split into two distinct and largely independent parts

 
***********************************************************************************************************************

The first part UE4 :

 Solitons and Integrable System: Analytic Approach

 

(V.B. Matveev, 40h and 10 CE)



will be devoted to the analytic aspects of the theory, from the Inverse Scattering Problem to the methods of algebraic geometry and of the isomonodromic deformation theory. It will also serve as a brief and useful introduction to the geometry of algebraic curves and to the Riemann-Hilbert problems. A list of subjects discussed in this first part of the course is as follows:
 
* Integrable systems associated to Schrödinger's and Dirac's differential operators on the line. Lax representation for the Korteweg - de Vries and for the non-linear Schrödinger equations.
 
* Elements of  the Quantum Scattering Theory. Jost solutions. Reflectionless potentials.


* Darboux transformations. Elementary constructions of multisoliton solutions.
 
* Integrals of motion for integrable PDE and trace formulae.
 
* Schrödinger's operator with periodic potential. Finite band potentials and algebraic curves.
 
* KP equation and its solitons.
 
* Analysis on compact Riemann surfaces; genus, canonical cycles and meromorphic differentials ; abelian integrals and their periods; period matrix.
 
* Riemann-Roch theorem and Riemann's inequality.
 
* Abstract theta functions. The Riemann theta function and Jacobi inversion problem.
 
* Solutions of the Korteweg de Vries equation and hyperelliptic curves. Baker–Akhiezer fonctions. Integration of the Kadomtsev–Petviashvily equation.
 
* Weierstrass points of algebraic curves and the classes of solutions of the KP equation which reduce to solutions of the Boussinesq equation.
 
* The Schottki problem. Classical Schottki groups and the parametrisation of the nonsingular real solutions of the KP equation.
 
* Matrix Baker–Akhiezer functions. Integration of the Sine-Gordon equation and of the non-linear Schrödinger equation.
 
* Solitons as degenerate algebro-geometric solutions.
 
* Lax pairs with variable spectral parameter. Einstein's equation in vacuum with axial symmetry. Applications of the algebro-geometric formalism to General Relativity.
 
* Isomonodromic deformations, Riemann-Hilbert problem and applications to integrable systems; Schlesinger systems and their connections with the Riemann-Hilbert problems. Schlesinger systems which are integrable in terms of theta functions. Painlevé equation.
 
 
***********************************************************************************************************************
 
The second part of the course UE5:
 

 Solitons and Integrable System: Algebraic Approach

 

(M.A. Semenov-Tian-Shansky, 40h et 10 CE)

 

will discuss the hidden symmetry of integrable systems and their relations with Lie groups and Lie algebras. The basic notions which yield a key to the geometric understanding of integrable systems are the classical r-matrices and the classical Yang-Baxter equation. These notions are very rich from an algebraic point of view and allow to treat in a unified way a vast number of examples, ranging from the equations of classical mechanics studied in the 19th century to the nonlinear partial differential equations (like Korteweg-de Vries or Sine-Gordon equations). They are also fundamental in the semi-classical study of quantum groups, thus giving a link between the classical and quantum theories of integrable systems.

The program of this part of the course is summarised here:
 
* Introduction: Symplectic manifolds; Poisson manifolds, symplectic leaves and stratification of Poisson manifolds.
 
* Lie–Poisson brackets and the theory of coadjoint orbits of Lie groups.
 
* Reduction theory for Poisson manifolds.
 
* The theory of r-matrices and the factorisation theorem.
 
* Integrable systemes associated to finite dimensional Lie algebras. Toda lattice.
 
* Loop algebras and Lax representations with spectral parameter.
 
* Riemann–Hilbert problem and factorisation in loop groups; Birkhoff–Grothendieck theorem.
 
* Lax equations with spectral parameter and algebraic geometry; linearization theorem.
 
* Examples of integrables systems associated to affine Lie algebras; periodic Toda lattice; the integrable cases of solid body motion.
 
* Zero curvature equations and central extensions of loop algebras; classification of their coadjoint orbits.
 
* Construction of local integrals of motion.
 
* Dressing transformations and homogeneus spaces of loop groups associated to integrable systems .
 
* Generalised Korteweg-de Vries equations; Drinfeld-Sokolov theory.
 
* Poisson–Lie groups and zero curvature equations on lattices. Dressing transformations as a non-linear version of the theory of coadjoint orbits.
 
* Introduction to quantum group theory. Quantum R-matrices; Yang–Baxter equation; the role of Hopf's axiom ; q-deformed enveloping algebreas.
 
The program will give the students an introduction to the current research subjects. According to the their taste, students may pursue the study of the more abstract aspects of the theory, or choose its more practical applications, for instance in non-linear optics, condensed matter physics or astrophysics.

 
BIBLIOGRAPHY
 
 
* D. Mumford. Tata lectures on thêta, vol 1,2, Basel Birkhauser (1983-1984).
 
* V.B. Matveev, M. Salle. Darboux transformations and Solitons. Springer-Verlag ser. Studies in Nonlinear Dynamics, 1991.
 
* E. Belokolos, A. Bobenko, A. Its, V. Enolskij and V.B. Matveev. Algebro-geometrical Approach to the Nonlinear Integrable Systems, Springer-Verlag, 1994.
 
* L. Faddeev and L. Tahtadjian. Hamiltonian Approach in the Theory of Solitons, Springer-Verlag, 1986.
 
* A.G. Reyman and M.A. Semenov-Tian-Shansky. Group-theoretical methods in the theory of Integrable systems. II. In : Encyclopaedia of Mathematical Sciences, 16. Springer-Verlag, Berlin, 1994. vi+341 pp.
 
* N. Bogolubov, A. Izergin and V. Korepin. Correlation functions of Integrable systems and quantum inverse methode. Cambridge Univ. Press 1994.
 
* S. Novikov, I. Gelfand, I. Krichever, B. Dubrovin and V.B. Matveev. Integrable systems. London Math. Soc. Lect. notes v. 61, Cambridge Univ. Press 1981.
 
* S. Novikov, S. Manakov,V. Zakharov and L. Pitaevskij. Theory of Solitons. Academic Press 1982.
 
* E. Lieb and D. Mattice. Mathematical Physics in one dimension. New York-London : Academic Press, 1966.
 
* O. Babelon, D. Bernard and M. Talon. Introduction to Classical Integrable Systems. Cambridge Monographs of Mathematical Physics, Cambridge University Press, Cambridge 2003.
 
* Yu. B. Suris. The problem of integrable discretization : Hamiltonian approach. Basel : Birkhäuser, 2003. 1070 pp. Progress in Mathematics, Vol. 219.
 
 



 
 

 Reourn to the MMA2 homepage (English version)

 Version
française