171 research outputs found
Spectrally accurate space-time solution of Hamiltonian PDEs
Recently, the numerical solution of multi-frequency, highly-oscillatory
Hamiltonian problems has been attacked by using Hamiltonian Boundary Value
Methods (HBVMs) as spectral methods in time. When the problem derives from the
space semi- discretization of (possibly Hamiltonian) partial differential
equations (PDEs), the resulting problem may be stiffly-oscillatory, rather than
highly-oscillatory. In such a case, a different implementation of the methods
is needed, in order to gain the maximum efficiency.Comment: 17 pages, 3 figure
Adaptive Energy Preserving Methods for Partial Differential Equations
A method for constructing first integral preserving numerical schemes for
time-dependent partial differential equations on non-uniform grids is
presented. The method can be used with both finite difference and partition of
unity approaches, thereby also including finite element approaches. The schemes
are then extended to accommodate -, - and -adaptivity. The method is
applied to the Korteweg-de Vries equation and the Sine-Gordon equation and
results from numerical experiments are presented.Comment: 27 pages; some changes to notation and figure
Line Integral solution of Hamiltonian PDEs
In this paper, we report about recent findings in the numerical solution of Hamiltonian Partial Differential Equations (PDEs), by using energy-conserving line integral methods in the Hamiltonian Boundary Value Methods (HBVMs) class. In particular, we consider the semilinear wave equation, the nonlinear Schrödinger equation, and the Korteweg–de Vries equation, to illustrate the main features of this novel approach
Poisson integrators
An overview of Hamiltonian systems with noncanonical Poisson structures is
given. Examples of bi-Hamiltonian ode's, pde's and lattice equations are
presented. Numerical integrators using generating functions, Hamiltonian
splitting, symplectic Runge-Kutta methods are discussed for Lie-Poisson systems
and Hamiltonian systems with a general Poisson structure. Nambu-Poisson systems
and the discrete gradient methods are also presented.Comment: 30 page
Geometric numerical schemes for the KdV equation
Geometric discretizations that preserve certain Hamiltonian structures at the
discrete level has been proven to enhance the accuracy of numerical schemes. In
particular, numerous symplectic and multi-symplectic schemes have been proposed
to solve numerically the celebrated Korteweg-de Vries (KdV) equation. In this
work, we show that geometrical schemes are as much robust and accurate as
Fourier-type pseudo-spectral methods for computing the long-time KdV dynamics,
and thus more suitable to model complex nonlinear wave phenomena.Comment: 22 pages, 14 figures, 74 references. Other author's papers can be
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