4,976 research outputs found
The topological structure of the vortices in the O(n) symmetric TDGL model
In the light of --mapping method and topological current theory, the
topological structure of the vortex state in TDGL model and the topological
quantization of the vortex topological charges are investigated. It is pointed
out that the topological charges of the vortices in TDGL model are described by
the Winding numbers of --mapping which are determined in terms of the
Hopf indices and the Brouwer degrees of --mapping.Comment: 9 pages, LaTe
MiniMax Entropy Network: Learning Category-Invariant Features for Domain Adaptation
How to effectively learn from unlabeled data from the target domain is
crucial for domain adaptation, as it helps reduce the large performance gap due
to domain shift or distribution change. In this paper, we propose an
easy-to-implement method dubbed MiniMax Entropy Networks (MMEN) based on
adversarial learning. Unlike most existing approaches which employ a generator
to deal with domain difference, MMEN focuses on learning the categorical
information from unlabeled target samples with the help of labeled source
samples. Specifically, we set an unfair multi-class classifier named
categorical discriminator, which classifies source samples accurately but be
confused about the categories of target samples. The generator learns a common
subspace that aligns the unlabeled samples based on the target pseudo-labels.
For MMEN, we also provide theoretical explanations to show that the learning of
feature alignment reduces domain mismatch at the category level. Experimental
results on various benchmark datasets demonstrate the effectiveness of our
method over existing state-of-the-art baselines.Comment: 8 pages, 6 figure
Classification of Quench Dynamical Behaviours in Spinor Condensates
Thermalization of isolated quantum systems is a long-standing fundamental
problem where different mechanisms are proposed over time. We contribute to
this discussion by classifying the diverse quench dynamical behaviours of
spin-1 Bose-Einstein condensates, which includes well-defined quantum collapse
and revivals, thermalization, and certain special cases. These special cases
are either nonthermal equilibration with no revival but a collapse even though
the system has finite degrees of freedom or no equilibration with no collapse
and revival. Given that some integrable systems are already shown to
demonstrate the weak form of eigenstate thermalization hypothesis (ETH), we
determine the regions where ETH holds and fails in this integrable isolated
quantum system. The reason behind both thermalizing and nonthermalizing
behaviours in the same model under different initial conditions is linked to
the discussion of `rare' nonthermal states existing in the spectrum. We also
propose a method to predict the collapse and revival time scales and how they
scale with the number of particles in the condensate. We use a sudden quench to
drive the system to non-equilibrium and hence the theoretical predictions given
in this paper can be probed in experiments.Comment: 14 pages, 16 figure
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