2,104 research outputs found
Hopf Map and Quantization on Sphere
Quantization of a system constrained to move on a sphere is considered by
taking a square root of the ``on sphere condition''. We arrive at the fibre
bundle structure of the Hopf map in the cases of and . This
leads to more geometrical understanding of monopole and instanton gauge
structures that emerge in the course of quantization.Comment: 9 pages, LaTeX2e, uses amsmath.st
Inequivalent Quantization in the Skyrme Model
Quantum mechanics on manifolds is not unique and in general infinite number
of inequivalent quantizations can be considered. They are specified by the
induced spin and the induced gauge structures on the manifold. The
configuration space of collective mode in the Skyrme model can be identified
with and thus the quantization is not unique. This leads to the
different predictions for the physical observables.Comment: 16 pages, LaTeX2
Lost equivalence of nonlinear sigma and models on noncommutative space
We show that the equivalence of nonlinear sigma and models which is
valid on the commutative space is broken on the noncommutative space. This
conclusion is arrived at through investigation of new BPS solitons that do not
exist in the commutative limit.Comment: 17 pages, LaTeX2
Anveshak - A Groundtruth Generation Tool for Foreground Regions of Document Images
We propose a graphical user interface based groundtruth generation tool in
this paper. Here, annotation of an input document image is done based on the
foreground pixels. Foreground pixels are grouped together with user interaction
to form labeling units. These units are then labeled by the user with the user
defined labels. The output produced by the tool is an image with an XML file
containing its metadata information. This annotated data can be further used in
different applications of document image analysis.Comment: Accepted in DAR 201
COCO_TS Dataset: Pixel-level Annotations Based on Weak Supervision for Scene Text Segmentation
The absence of large scale datasets with pixel-level supervisions is a
significant obstacle for the training of deep convolutional networks for scene
text segmentation. For this reason, synthetic data generation is normally
employed to enlarge the training dataset. Nonetheless, synthetic data cannot
reproduce the complexity and variability of natural images. In this paper, a
weakly supervised learning approach is used to reduce the shift between
training on real and synthetic data. Pixel-level supervisions for a text
detection dataset (i.e. where only bounding-box annotations are available) are
generated. In particular, the COCO-Text-Segmentation (COCO_TS) dataset, which
provides pixel-level supervisions for the COCO-Text dataset, is created and
released. The generated annotations are used to train a deep convolutional
neural network for semantic segmentation. Experiments show that the proposed
dataset can be used instead of synthetic data, allowing us to use only a
fraction of the training samples and significantly improving the performances
Berry Connections and Induced Gauge Fields in Quantum Mechanics on Sphere
Quantum mechanics on sphere is studied from the viewpoint that the
Berry's connection has to appear as a topological term in the effective action.
Furthermore we show that this term is the Chern-Simons term of gauge variables
that correspond to the extra degrees of freedom of the enlarged space.Comment: 12 pages, LaTeX2
Noncommutative Chern-Simons Soliton
We have studied the noncommutative extension of the relativistic
Chern-Simons-Higgs model, in the first non-trivial order in , with only
spatial noncommutativity. Both Lagrangian and Hamiltonian formulations of the
problem have been discussed, with the focus being on the canonical and
symmetric forms of the energy-momentum tensor. In the Hamiltonian scheme,
constraint analysis and the induced Dirac brackets have been provided. The
spacetime translation generators and their actions on the fields are discussed
in detail.
The effects of noncommutativity on the soliton solutions have been analysed
thoroughly and we have come up with some interesting observations. Considering
the {\it{relative}} strength of the noncommutative effects, we have shown that
there is a universal character in the noncommutative correction to the magnetic
field - it depends {\it{only}} on . On the other hand, in the cases of
all other observables of physical interest, such as the potential profile,
soliton mass or the electric field, as well as , (comprising
solely of commutative Chern-Simons-Higgs model parameters), appear on similar
footings. This phenomenon is a new finding which has come up in the present
analysis.
Lastly, we have pointed out a generic problem in the NC extension of the
models, in the form of a mismatch between the BPS dynamical equation and the
full variational equations of motion, to . This mismatch indicates
that the analysis is not complete as it brings in to fore the ambiguities in
the definition of the energy-momentum tensor in a noncommutative theory.Comment: 21 page
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