Results 11 to 20 of about 1,079 (166)

A SYMPLECTIC INTEGRATOR FOR HILL'S EQUATIONS [PDF]

open access: yesThe Astronomical Journal, 2010
Hill's equations are an approximation that is useful in a number of areas of astrophysics including planetary rings and planetesimal disks. We derive a symplectic method for integrating Hill's equations based on a generalized leapfrog. This method is implemented in the parallel N-body code, PKDGRAV and tested on some simple orbits.
Quinn, T.   +3 more
openaire   +2 more sources

Multiscale Geometric Integration of Deterministic and Stochastic Systems [PDF]

open access: yes, 2011
In order to accelerate computations and improve long time accuracy of numerical simulations, this thesis develops multiscale geometric integrators. For general multiscale stiff ODEs, SDEs, and PDEs, FLow AVeraging integratORs (FLAVORs) have been ...
Tao, Molei
core   +1 more source

Symplectic groupoids for Poisson integrators

open access: yesJournal of Geometry and Physics, 2023
We use local symplectic Lie groupoids to construct Poisson integrators for generic Poisson structures. More precisely, recursively obtained solutions of a Hamilton-Jacobi-like equation are interpreted as Lagrangian bisections in a neighborhood of the unit manifold, that, in turn, give Poisson integrators.
openaire   +2 more sources

Anomaly in symplectic integrator [PDF]

open access: yesPhysics Letters A, 2007
6 pages, no ...
openaire   +2 more sources

Variational Integrators [PDF]

open access: yes, 2004
Variational integrators are a class of discretizations for mechanical systems which are derived by discretizing Hamilton's principle of stationary action.
West, Matthew
core   +1 more source

Symplectic integrators for spin systems [PDF]

open access: yesPhysical Review E, 2014
We present a symplectic integrator, based on the canonical midpoint rule, for classical spin systems in which each spin is a unit vector in $\mathbb{R}^3$. Unlike splitting methods, it is defined for all Hamiltonians, and is $O(3)$-equivariant. It is a rare example of a generating function for symplectic maps of a noncanonical phase space. It yields an
Robert I. McLachlan   +2 more
openaire   +3 more sources

Coupling policy iteration with semi-definite relaxation to compute accurate numerical invariants in static analysis [PDF]

open access: yesLogical Methods in Computer Science, 2012
We introduce a new domain for finding precise numerical invariants of programs by abstract interpretation. This domain, which consists of level sets of non-linear functions, generalizes the domain of linear "templates" introduced by Manna ...
Assalé Adjé   +2 more
doaj   +1 more source

On the Nonlinear Stability of Symplectic Integrators [PDF]

open access: yesBIT Numerical Mathematics, 2004
The paper deals mainly with the problem of achieving stability for symplectic numerical integrators by the mean of studying the topological equivalence of the level sets of the original Hamiltonian and those of the modified Hamiltonian associated to the numerical integrators.
Mclachlan, Robert Iain.   +2 more
openaire   +1 more source

Tuning Symplectic Integrators is Easy and Worthwhile [PDF]

open access: yesCommunications in Computational Physics, 2022
Many applications in computational physics that use numerical integrators based on splitting and composition can benefit from the development of optimized algorithms and from choosing the best ordering of terms. The cost in programming and execution time is minimal, while the performance improvements can be large.
openaire   +3 more sources

Fourth-order symplectic integration [PDF]

open access: yesPhysica D: Nonlinear Phenomena, 1990
Die Autoren behandeln die Integration der Hamiltonschen Gleichungen unter Anwendung einer expliziten Vierter-Ordnung-Methode. Diese bewahrt die Eigenschaft, daß eine zeitliche Entwicklung eines solchen Systems eine kanonische Transformation aus den Anfangsbedingungen bis zum Endzustand erhält.
Forest, E., Ruth, R.D.
openaire   +2 more sources

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