Zusammenfassung
Hamiltonian dynamics can be used to produce distant proposals for the
Metropolis algorithm, thereby avoiding the slow exploration of the state space
that results from the diffusive behaviour of simple random-walk proposals.
Though originating in physics, Hamiltonian dynamics can be applied to most
problems with continuous state spaces by simply introducing fictitious
"momentum" variables. A key to its usefulness is that Hamiltonian dynamics
preserves volume, and its trajectories can thus be used to define complex
mappings without the need to account for a hard-to-compute Jacobian factor - a
property that can be exactly maintained even when the dynamics is approximated
by discretizing time. In this review, I discuss theoretical and practical
aspects of Hamiltonian Monte Carlo, and present some of its variations,
including using windows of states for deciding on acceptance or rejection,
computing trajectories using fast approximations, tempering during the course
of a trajectory to handle isolated modes, and short-cut methods that prevent
useless trajectories from taking much computation time.
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