Symplectic group

About: Symplectic group is a research topic. Over the lifetime, 2802 publications have been published within this topic receiving 57445 citations.

Numerical Hamiltonian Problems

Abstract: Hamiltonian Systems. Examples of Hamiltonian Systems. Symplecticness. The solution operator. Preservation of area. Checking preservation of area: Jacobians. Checking preservation of area: differential forms. Symplectic transformations. Conservation of volume. Numerical Methods. Numerical integrators. Stiff problems. Runge-Kutta methods. Partitioned Runge-Kutta methods. Runge-Kutta-Nystrom methods. Composition of methods - adjoints. Order conditions. Order conditions for Runge-Kutta methods. The local error in Runge-Kutta methods. Order conditions for PRK methods. The local error in Partitioned Runge-Kutta methods. Order conditions for Runge-Kutta-Nystrom methods. The local error in Runge-Kutta-Nystrom mehthods. Implementation. Variable step sizes. Embedded pairs. Numerical experience with variable step sizes. Implementing implicit methods. Fourth-order Gauss method. Symplectic integration. Symplectic methods. Symplectic Runge-Kutta methods. Symplectic partitioned Runge-Kutta methods. Symplectic Runge-Kutta-Nystrom methods. Necessity of the symplecticness conditions. Symplectic order conditions. Prelimiaries. Order conditions for symplectic RK methods. Order conditions for symplectic PRK methods. Order conditions for symplectic RKN methods. Homogenous form of the order conditions. Available symplectic methods. Symplecticness of the Gauss methods. Diagonally implicity Runge-Kutta methods. Other symplectic Runge-Kutta methods. Explicit partitioned Runge-Kutta methods. Available symplectic Runge-Kutta-Nystrom methods. Numerical experiments. A comparison of symplectic integrators. Variable step sizes for symplectic methods. Conclusions and recommendations. Properties of symplectic integrators. Backward error interpretation. An alternative approach. Conservation of energy. KAM theory. Generating functions. The concept of generating function. Hamilton-Jacobi equations. Integrators based on generating functions. Generating functions for RK methods. Canonical order theory. Lie formalism. The Poisson bracket. Lie operators and Lie series. The Baker-Campbell-Hausdorff formula. Application to fractional-step methods. Extension to the non-Hamilton case. High-order methods. High-order Lie methods. High-order Runge-Kutta-Nystrom methods. A comparison of order 8 symplectic integrators. Extensions. Partitioned Runge-Kutta methods for nonseparable Hamiltonian systems. Canonical B-series. Conjugate symplectic methods. Trapezoidal rule. Constrained systems. General Poisson structures. Multistep methods. Partial differential equations. Reversable systems. Volume preserving flows.

Symplectic geometry and analytical mechanics

Abstract: I. Symplectic vector spaces and symplectic vector bundles.- 1: Symplectic vector spaces.- 1. Properties of exterior forms of arbitrary degree.- 2. Properties of exterior 2-forms.- 3. Symplectic forms and their automorphism groups.- 4. The contravariant approach.- 5. Orthogonality in a symplectic vector space.- 6. Forms induced on a vector subspace of a symplectic vector space.- 7. Additional properties of Lagrangian subspaces.- 8. Reduction of a symplectic vector space. Generalizations.- 9. Decomposition of a symplectic form.- 10. Complex structures adapted to a symplectic structure.- 11. Additional properties of the symplectic group.- 2: Symplectic vector bundles.- 12. Properties of symplectic vector bundles.- 13. Orthogonality and the reduction of a symplectic vector bundle.- 14. Complex structures on symplectic vector bundles.- 3: Remarks concerning the operator ? and Lepage's decomposition theorem.- 15. The decomposition theorem in a symplectic vector space.- 16. Decomposition theorem for exterior differential forms.- 17. A first approach to Darboux's theorem.- II. Semi-basic and vertical differential forms in mechanics.- 1. Definitions and notations.- 2. Vector bundles associated with a surjective submersion.- 3. Semi-basic and vertical differential forms.- 4. The Liouville form on the cotangent bundle.- 5. Symplectic structure on the cotangent bundle.- 6. Semi-basic differential forms of arbitrary degree.- 7. Vector fields and second-order differential equations.- 8. The Legendre transformation on a vector bundle.- 9. The Legendre transformation on the tangent and cotangent bundles.- 10. Applications to mechanics: Lagrange and Hamilton equations.- 11. Lagrange equations and the calculus of variations.- 12. The Poincare-Cartan integral invariant.- 13. Mechanical systems with time dependent Hamiltonian or Lagrangian functions.- III. Symplectic manifolds and Poisson manifolds.- 1. Symplectic manifolds definition and examples.- 2. Special submanifolds of a symplectic manifold.- 3. Symplectomorphisms.- 4. Hamiltonian vector fields.- 5. The Poisson bracket.- 6. Hamiltonian systems.- 7. Presymplectic manifolds.- 8. Poisson manifolds.- 9. Poisson morphisms.- 10. Infinitesimal automorphisms of a Poisson structure.- 11. The local structure of Poisson manifolds.- 12. The symplectic foliation of a Poisson manifold.- 13. The local structure of symplectic manifolds.- 14. Reduction of a symplectic manifold.- 15. The Darboux-Weinstein theorems.- 16. Completely integrable Hamiltonian systems.- 17. Exercises.- IV. Action of a Lie group on a symplectic manifold.- 1. Symplectic and Hamiltonian actions.- 2. Elementary properties of the momentum map.- 3. The equivariance of the momentum map.- 4. Actions of a Lie group on its cotangent bundle.- 5. Momentum maps and Poisson morphisms.- 6. Reduction of a symplectic manifold by the action of a Lie group.- 7. Mutually orthogonal actions and reduction.- 8. Stationary motions of a Hamiltonian system.- 9. The motion of a rigid body about a fixed point.- 10. Euler's equations.- 11. Special formulae for the group SO(3).- 12. The Euler-Poinsot problem.- 13. The Euler-Lagrange and Kowalevska problems.- 14. Additional remarks and comments.- 15. Exercises.- V. Contact manifolds.- 1. Background and notations.- 2. Pfaffian equations.- 3. Principal bundles and projective bundles.- 4. The class of Pfaffian equations and forms.- 5. Darboux's theorem for Pfaffian forms and equations.- 6. Strictly contact structures and Pfaffian structures.- 7. Protectable Pfaffian equations.- 8. Homogeneous Pfaffian equations.- 9. Liouville structures.- 10. Fibered Liouville structures.- 11. The automorphisms of Liouville structures.- 12. The infinitesimal automorphisms of Liouville structures.- 13. The automorphisms of strictly contact structures.- 14. Some contact geometry formulae in local coordinates.- 15. Homogeneous Hamiltonian systems.- 16. Time-dependent Hamiltonian systems.- 17. The Legendre involution in contact geometry.- 18. The contravariant point of view.- Appendix 1. Basic notions of differential geometry.- 1. Differentiable maps, immersions, submersions.- 2. The flow of a vector field.- 3. Lie derivatives.- 4. Infinitesimal automorphisms and conformai infinitesimal transformations.- 5. Time-dependent vector fields and forms.- 6. Tubular neighborhoods.- 7. Generalizations of Poincare's lemma.- Appendix 2. Infinitesimal jets.- 1. Generalities..- 2. Velocity spaces.- 3. Second-order differential equations.- 4. Sprays and the exponential mapping.- 5. Covelocity spaces.- 6. Liouville forms on jet spaces.- Appendix 3. Distributions, Pfaffian systems and foliations.- 1. Distributions and Pfaffian systems.- 2. Completely integrable distributions.- 3. Generalized foliations defined by families of vector fields.- 4. Differentiable distributions of constant rank.- Appendix 4. Integral invariants.- 1. Integral invariants of a vector field.- 2. Integral invariants of a foliation.- 3. The characteristic distribution of a differential form.- Appendix 5. Lie groups and Lie algebras.- 1. Lie groups and Lie algebras generalities.- 2. The exponential map.- 3. Action of a Lie group on a manifold.- 4. The adjoint and coadjoint representations.- 5. Semi-direct products.- 6. Notions regarding the cohomology of Lie groups and Lie algebras.- 7. Affine actions of Lie groups and Lie algebras.- Appendix 6. The Lagrange-Grassmann manifold.- 1. The structure of the Lagrange-Grassmann manifold.- 2. The signature of a Lagrangian triplet.- 3. The fundamental groups of the symplectic group and of the Lagrange-Grassmann manifold.- Appendix 7. Morse families and Lagrangian submanifolds.- 1. Lagrangian submanifolds of a cotangent bundle.- 2. Hamiltonian systems and first-order partial differential equations.- 3. Contact manifolds and first-order partial differential equations.- 4. Jacobi's theorem.- 5. The Hamilton-Jacobi equation for autonomous systems.- 6. The Hamilton-Jacobi equation for non autonomous systems.

Linear Canonical Transformations and Their Unitary Representations

Abstract: We show that the group of linear canonical transformations in a 2N‐dimensional phase space is the real symplectic group Sp(2N), and discuss its unitary representation in quantum mechanics when the N coordinates are diagonal. We show that this Sp(2N) group is the well‐known dynamical group of the N‐dimensional harmonic oscillator. Finally, we study the case of n particles in a q‐dimensional oscillator potential, for which N = nq, and discuss the chain of groups Sp(2nq)⊃Sp(2n)× O (q). An application to the calculation of matrix elements is given in a following paper.