6,473 research outputs found
Topological Electropoles in 4+1 Dimensional EYMCS Theory
A class of explicit exact solutions of Einstein Yang Mills Chern Simons
(EYMCS) theory corresponding to topological solitons carrying non-Abelian
topological electric charge is obtained. This verifies a conjecture made in
Ref.[1,2] regarding the stabilization of the corresponding charged
configurations in the theory without gravity .Comment: 11 pages ,Plain TeX,IOPB/BBSR/94-11. Minor typos in eqns(4),(7),
(13a),(13b),(21) correcte
On the relationship between the modifications to the Raychaudhuri equation and the canonical Hamiltonian structures
The problem of obtaining canonical Hamiltonian structures from the equations
of motion, without any knowledge of the action, is studied in the context of
the spatially flat Friedmann-Robertson-Walker models. Modifications to
Raychaudhuri equation are implemented independently as quadratic and cubic
terms of energy density without introducing additional degrees of freedom.
Depending on their sign, modifications make gravity repulsive above a curvature
scale for matter satisfying strong energy condition, or more attractive than in
the classical theory. Canonical structure of the modified theories is
determined demanding that the total Hamiltonian be a linear combination of
gravity and matter Hamiltonians. In the quadratic repulsive case, the modified
canonical phase space of gravity is a polymerized phase space with canonical
momentum as inverse trigonometric function of Hubble rate; the canonical
Hamiltonian can be identified with the effective Hamiltonian in loop quantum
cosmology. The repulsive cubic modification results in a `generalized
polymerized' canonical phase space. Both of the repulsive modifications are
found to yield singularity avoidance. In contrast, the quadratic and cubic
attractive modifications result in a canonical phase space in which canonical
momentum is non-trigonometric and singularities persist. Our results hint on
connections between repulsive/attractive nature of modifications to gravity
arising from gravitational sector and polymerized/non-polymerized gravitational
phase space.Comment: 22 pages with two new plots. Discussion on uniqueness added, and
possible links with existing models expanded. Periodicity for 'generalized
polymerized' theory and its comparison with standard polymerization
discussed. References added. To appear in CQ
Topological Soliton Multiplets in 4+1 Dimensional YMCS Theory
We generalize our results on charged topological solitons (CTS) in
dimensional Yang-Mills-Chern-Simons (YMCS) theory to . The
multiplet structure of two classes of solitons associated with the
maximal embeddings and and the vital role of the multiplet of
topological currents is clarified. In the case of the first embedding one
obtains a plet of CTS. In the second, for , one obtains
neutral solitons which, though (classically) spinless, have magnetic moments.
For , after modding out the above mentioned non-particulate feature,
one obtains plets of CTS.Comment: (minor semantic changes), 21
Identifying Parkinson’s Patients: A Functional Gradient Boosting Approach
Parkinson’s, a progressive neural disorder, is difficult to identify due to the hidden nature of the symptoms associated. We present a machine learning approach that uses a definite set of features obtained from the Parkinson’s Progression Markers Initiative (PPMI) study as input and classifies them into one of two classes: PD (Parkinson’s disease) and HC (Healthy Control). As far as we know this is the first work in applying machine learning algorithms for classifying patients with Parkinson’s disease with the involvement of domain expert during the feature selection process. We evaluate our approach on 1194 patients acquired from Parkinson’s Progression Markers Initiative and show that it achieves a state-of-the-art performance with minimal feature engineering
Fourth Generation Parity
We present a very simple 4th-generation (4G) model with an Abelian gauge
interaction under which only the 4G fermions have nonzero charge. The U(1)
gauge symmetry can have a Z_2 residual discrete symmetry (4G-parity), which can
stabilize the lightest 4G particle (L4P). When the 4G neutrino is the L4P, it
would be a neutral and stable particle and the other 4G fermions would decay
into the L4P leaving the trace of missing energy plus the standard model
fermions. Because of the new symmetry, the 4G particle creation and decay modes
are different from those of the sequential 4G model, and the 4G particles can
be appreciably lighter than typical experimental bounds.Comment: Version accepted for publication in PR
Giant Goos-H\"anchen shift in Scattering: the role of interfering Localized Plasmon modes
The longitudinal and the transverse beam shifts, namely, the Goos-H\"anchen
(GH) and the Spin-Hall (SH) shifts are usually observed at planar interfaces.
It has recently been shown that the transverse SH shift may also arise due to
scattering of plane waves. Here, we show that analogous in-plane (longitudinal)
shift also exist in scattering of plane waves from micro/nano systems. We study
both the GH and the SH shifts in plasmonic metal nanoparticles/ nanostructures
and dielectric micro-particles employing a unified framework that utilizes the
transverse components of the Poynting vector of the scattered wave. The results
demonstrate that interference of neighboring resonance modes in plasmonic
nanostructures (e.g., electric dipolar and quadrupolar modes in metal spheres)
leads to giant enhancement of GH shift in scattering from such systems. We also
unravel interesting correlations between these shifts with the polarimetry
parameters, diattenuation and retardance.Comment: 4 pages, 3 figure
Constraining the mixing matrix for Standard Model with four generations: time dependent and semi-leptonic CP asymmetries in , and
Using existing experimental information from K, B and D decays as well as
electroweak precision tests and oblique parameters, we provide constraints and
correlations on the parameters of the 4X4 mixing matrix for the Standard Model
with four generations (SM4). We emphasize that some correlations amongst the
parameters have important repercussions for key observables. We work with a
particular representation of this matrix which is highly suited for extracting
information from B-decays. Implications of the resulting constraints for time
dependent and semileptonic CP asymmetries for , and for are
also given. While we show that the semi-leptonic asymmetries may be
significantly enhanced in SM4 over the SM, there are important constraints and
correlations with other observables. In this context we suggest that existing
data from B-factories taken on and , and in the
relevant continuum be used to constrain the semi-leptonic asymmetries for
, as well as their linear combination. Of course, the data from the
Tevatron and LHCb experiments can provide non-trivial tests of SM4 as well.Comment: 20 pages, 22 figures, few references and a footnote adde
The Quark Gluon Pion Plasma
While it is commonly believed that there is a {\it direct} transition from
the hadronic to a quark gluon phase at high temperature, it would be
prejudicial to rule out a sequence of dynamically generated intermediate
scales. Using as guide, an effective lagrangian with unconfined gluons and
constituent quarks, interacting with a chiral multiplet, we examine a scenario
in which the system undergoes first-order transitions at , the
compositeness scale of the pions, at , the scale for spontaneous
chiral symmetry breaking, and at , the confinement temperature.
We find that at current energies, it is likely that the formation temperature
of the plasma, , and that this is therefore a quark gluon
pion plasma (QGPP) rather than the usual quark gluon plasma (QGP). We propose
some dilepton-related signatures of this scenario.Comment: Rewritten, new figure
An Efficient Vein Pattern-based Recognition System
This paper presents an efficient human recognition system based on vein
pattern from the palma dorsa. A new absorption based technique has been
proposed to collect good quality images with the help of a low cost camera and
light source. The system automatically detects the region of interest from the
image and does the necessary preprocessing to extract features. A Euclidean
Distance based matching technique has been used for making the decision. It has
been tested on a data set of 1750 image samples collected from 341 individuals.
The accuracy of the verification system is found to be 99.26% with false
rejection rate (FRR) of 0.03%.Comment: IEEE Publication format, International Journal of Computer Science
and Information Security, IJCSIS, Vol. 8 No. 1, April 2010, USA. ISSN 1947
5500, http://sites.google.com/site/ijcsis
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