29,145 research outputs found
An effective potential for one-dimensional matter-wave solitons in an axially inhomogeneous trap
We demonstrate that a tight transverse trap with the local frequency, , gradually varying in the longitudinal direction () induces
an effective potential for one-dimensional solitons in a self-attractive
Bose-Einstein condensate. An analytical approximation for this potential is
derived by means of a variational method. In the lowest approximation, the
potential is , with the soliton's norm (number of
atoms), and its intrinsic vorticity (if any). The results can be used to
devise nonuniform traps helping to control the longitudinal dynamics of the
solitons. Numerical verification of the analytical predictions will be
presented elsewhere.Comment: to be published in Physics Letters
VIME: Variational Information Maximizing Exploration
Scalable and effective exploration remains a key challenge in reinforcement
learning (RL). While there are methods with optimality guarantees in the
setting of discrete state and action spaces, these methods cannot be applied in
high-dimensional deep RL scenarios. As such, most contemporary RL relies on
simple heuristics such as epsilon-greedy exploration or adding Gaussian noise
to the controls. This paper introduces Variational Information Maximizing
Exploration (VIME), an exploration strategy based on maximization of
information gain about the agent's belief of environment dynamics. We propose a
practical implementation, using variational inference in Bayesian neural
networks which efficiently handles continuous state and action spaces. VIME
modifies the MDP reward function, and can be applied with several different
underlying RL algorithms. We demonstrate that VIME achieves significantly
better performance compared to heuristic exploration methods across a variety
of continuous control tasks and algorithms, including tasks with very sparse
rewards.Comment: Published in Advances in Neural Information Processing Systems 29
(NIPS), pages 1109-111
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