29,602 research outputs found
Composite Fermions and Landau Level Mixing in the Fractional Quantum Hall Effect
The reduction of the energy gap due to Landau level mixing, characterized by
the dimensionless parameter , has
been calculated by variational Monte Carlo for the fractional quantum Hall
effect at filling fractions and 1/5 using a modified version of
Jain's composite fermion wave functions. These wave functions exploit the
Landau level mixing already present in composite fermion wave functions by
introducing a partial Landau level projection operator. Results for the energy
gaps are consistent with experimental observations in -type GaAs, but we
conclude that Landau level mixing alone cannot account for the significantly
smaller energy gaps observed in -type systems.Comment: 11 pages, RevTex, 2 figures in compressed tar .ps forma
Unconstrained Scene Text and Video Text Recognition for Arabic Script
Building robust recognizers for Arabic has always been challenging. We
demonstrate the effectiveness of an end-to-end trainable CNN-RNN hybrid
architecture in recognizing Arabic text in videos and natural scenes. We
outperform previous state-of-the-art on two publicly available video text
datasets - ALIF and ACTIV. For the scene text recognition task, we introduce a
new Arabic scene text dataset and establish baseline results. For scripts like
Arabic, a major challenge in developing robust recognizers is the lack of large
quantity of annotated data. We overcome this by synthesising millions of Arabic
text images from a large vocabulary of Arabic words and phrases. Our
implementation is built on top of the model introduced here [37] which is
proven quite effective for English scene text recognition. The model follows a
segmentation-free, sequence to sequence transcription approach. The network
transcribes a sequence of convolutional features from the input image to a
sequence of target labels. This does away with the need for segmenting input
image into constituent characters/glyphs, which is often difficult for Arabic
script. Further, the ability of RNNs to model contextual dependencies yields
superior recognition results.Comment: 5 page
Eigenvalue spectrum for single particle in a spheroidal cavity: A Semiclassical approach
Following the semiclassical formalism of Strutinsky et al., we have obtained
the complete eigenvalue spectrum for a particle enclosed in an infinitely high
spheroidal cavity. Our spheroidal trace formula also reproduces the results of
a spherical billiard in the limit . Inclusion of repetition of each
family of the orbits with reference to the largest one significantly improves
the eigenvalues of sphere and an exact comparison with the quantum mechanical
results is observed upto the second decimal place for . The
contributions of the equatorial, the planar (in the axis of symmetry plane) and
the non-planar(3-Dimensional) orbits are obtained from the same trace formula
by using the appropriate conditions. The resulting eigenvalues compare very
well with the quantum mechanical eigenvalues at normal deformation. It is
interesting that the partial sum of equatorial orbits leads to eigenvalues with
maximum angular momentum projection, while the summing of planar orbits leads
to eigenvalues with except for L=1. The remaining quantum mechanical
eigenvalues are observed to arise from the 3-dimensional(3D) orbits. Very few
spurious eigenvalues arise in these partial sums. This result establishes the
important role of 3D orbits even at normal deformations.Comment: 17 pages, 7 ps figure
All tree level scattering amplitudes in Chern-Simons theories with fundamental matter
We show that Britto-Cachazo-Feng-Witten (BCFW) recursion relations can be
used to compute all tree level scattering amplitudes in terms of
scattering amplitude in Chern-Simons
(CS) theory coupled to matter in fundamental representation. As a byproduct, we
also obtain a recursion relation for the CS theory coupled to regular fermions,
even though in this case standard BCFW deformations do not have a good
asymptotic behaviour. Moreover at large , scattering can be
computed exactly to all orders in 't Hooft coupling as was done in earlier
works by some of the authors. In particular, for theory, it
was shown that scattering is tree level exact to all orders
except in the anyonic channel arXiv:1505.06571, where it gets renormalized by a
simple function of 't Hooft coupling. This suggests that it may be possible to
compute the all loop exact result for arbitrary higher point scattering
amplitudes at large .Comment: RevTEX 4.1, 5 pages+6 Appendices, 7 figures; V2 Published versio
Electromagnetic Form Factors and the Localization of Quark Orbital Angular Momentum in the Proton
A new picture is given of generalized parton distributions probed in
experiments in which the probe scale and the momentum transfer
\DD^{2} are well separated. Application of this picture to the
dependence of the form factors shows that gauge invariant quark
orbital angular momentum can be measured and indeed {\it localized} in the
transverse profile of the proton. A previous prediction that
is generalized to GPD
language. This prediction appears to have been confirmed by recent CEBAF data.Comment: 6 pages, 1 figure. To appear in DIS 2001, 9th International Workshop
on Deep Inelastic Scattering, Bologna, 27 April - 1 May, 200
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