A variational approach to homoclinic orbits in Hamiltonian systems.
A variational construction of chaotic trajectories for a Hamiltonian system on a torus
A geometric criterion for the existence of chaotic trajectories of a Hamiltonian system with two degrees of freedom and the configuration space a torus is given. As an application, positive topological entropy is established for a double pendulum problem.
A Viterbo-Hofer-Zehnder type result for hamiltonian inclusions
Abelian integrals for quadratic vector fields.
Abelian integrals of quadratic Hamiltonian vector fields with an invariant straight line.
We prove that the lowest upper bound for the number of isolated zeros of the Abelian integrals associated to quadratic Hamiltonian vector fields having a center and an invariant straight line after quadratic perturbations is one.
Abelian integrals related to Morse polynomials and perturbations of plane hamiltonian vector fields
Let be the real vector space of Abelian integralswhere is a fixed real polynomial, is an arbitrary real polynomial and , , is the interior of the oval of which surrounds the origin and tends to it as . We prove that if is a semiweighted homogeneous polynomial with only Morse critical points, then is a free finitely generated module over the ring of real polynomials , and compute its rank. We find the generators of in the case when is an arbitrary cubic polynomial. Finally we...
Abelian surfaces and Kowalewski's top
Abstract mechanical connection and Abelian reconstruction for almost Kähler manifolds.
A-cohomologie et opérateurs de récursion
Action minimizing invariant measures for positive definite Lagrangian systems.
Action-angle coordinates at singularities for analytic integrable systems.
Actions localement libres de groupes résolubles
Soient un groupe de Lie connexe de dimension , une action localement libre de classe de sur une variété compacte de dimension . Nous supposons qu’il existe dans l’algèbre de Lie de un champ tel que les valeurs propres de soient avec . Alors, nous montrons que est -conjuguée à une “action modèle" de sur un espace homogène où est un groupe de Lie contenant . Si , est uniquement déterminé par ; si , il y a deux groupes possibles, et nous pouvons donc donner une...
Addendum: Systems of Toda Type, Inverse Spectral Problems, and Representation Theory.
Addendum to: A Bound for the Fixed-Point Index of an Area-Preserving Map with Applications to Mechanics.
Addendum to "On the Variation in the Cohomology of the Symplectic Form of the Reduced Phase Space."
Adjoint methods for obstacle problems and weakly coupled systems of PDE
The adjoint method, recently introduced by Evans, is used to study obstacle problems, weakly coupled systems, cell problems for weakly coupled systems of Hamilton − Jacobi equations, and weakly coupled systems of obstacle type. In particular, new results about the speed of convergence of some approximation procedures are derived.
Affine Gelfand-Dickey Brackets and Holomorphic Vector Bundles.
Affinor structures in the oscillation theory
In this paper we consider the system of Hamiltonian differential equations, which determines small oscillations of a dynamical system with n parameters. We demonstrate that this system determines an affinor structure J on the phase space TRⁿ. If J² = ωI, where ω = ±1,0, the phase space can be considered as the biplanar space of elliptic, hyperbolic or parabolic type. In the Euclidean case (Rⁿ = Eⁿ) we obtain the Hopf bundle and its analogs. The bases of these bundles are, respectively, the projective...
Algebraic calculation of the energy eigenvalues for the nondegenerate three-dimensional Kepler-Coulomb potential.
Algebraic complete integrability of an integrable system of Beauville
We show that the Beauville’s integrable system on a ten dimensional moduli space of sheaves on a K3 surface constructed via a moduli space of stable sheaves on cubic threefolds is algebraically completely integrable, using O’Grady’s construction of a symplectic resolution of the moduli space of sheaves on a K3.