19,162 research outputs found
The Tensor Current Divergence Equation in U(1) Gauge Theories is Free of Anomalies
The possible anomaly of the tensor current divergence equation in U(1) gauge
theories is calculated by means of perturbative method. It is found that the
tensor current divergence equation is free of anomalies.Comment: Revtex4, 7 pages, 2 figure
Ions in solution: Density Corrected Density Functional Theory (DC-DFT)
Standard density functional approximations often give questionable results
for odd-electron radical complexes, with the error typically attributed to
self-interaction. In density corrected density functional theory (DC-DFT),
certain classes of density functional theory calculations are significantly
improved by using densities more accurate than the self-consistent densities.
We discuss how to identify such cases, and how DC-DFT applies more generally.
To illustrate, we calculate potential energy surfaces of HOCl and
HOHO complexes using various common approximate functionals, with
and without this density correction. Commonly used approximations yield wrongly
shaped surfaces and/or incorrect minima when calculated self consistently,
while yielding almost identical shapes and minima when density corrected. This
improvement is retained even in the presence of implicit solvent
Top quark forward-backward asymmetry and charge asymmetry in left-right twin Higgs model
In order to explain the Tevatron anomaly of the top quark forward-backward
asymmetry in the left-right twin Higgs model, we choose to give up
the lightest neutral particle of field as a stable dark matter
candidate. Then a new Yukawa interaction for is allowed, which can be
free from the constraint of same-sign top pair production and contribute
sizably to . Considering the constraints from the production rates of
the top pair (), the top decay rates and invariant mass
distribution, we find that this model with such new Yukawa interaction can
explain measured at the Tevatron while satisfying the charge
asymmetry measured at the LHC.Moreover, this model predicts a
strongly correlation between at the LHC and at the
Tevatron, i.e., increases as increases.Comment: 17 pages, 9 figures; matches the published versio
SPEAR Far Ultraviolet Spectral Images of the Cygnus Loop
We present far-ultraviolet (FUV) spectral images, measured at C IV 1550, He
II 1640, Si IV+O IV] 1400, and O III] 1664, of the entire Cygnus Loop, observed
with the Spectroscopy of Plasma Evolution from Astrophysical Radiation (SPEAR)
instrument, also known as FIMS. The spatial distribution of FUV emission
generally corresponds with a limb-brightened shell, and is similar to optical,
radio and X-ray images. The features found in the present work include a
``carrot'', diffuse interior, and breakout features, which have not been seen
in previous FUV studies. Shock velocities of 140-160 km/s is found from a line
ratio of O IV] to O III], which is insensitive not only to resonance scattering
but also to elemental abundance. The estimated velocity indicates that the fast
shocks are widespread across the remnant. By comparing various line ratios with
steady-state shock models, it is also shown that the resonance scattering is
widespread.Comment: 13 pages, 3 figures, 1 table, accepted for publication in ApJ
Effects of Line-tying on Resistive Tearing Instability in Slab Geometry
The effects of line-tying on resistive tearing instability in slab geometry
is studied within the framework of reduced magnetohydrodynamics
(RMHD).\citep{KadomtsevP1974,Strauss1976} It is found that line-tying has a
stabilizing effect. The tearing mode is stabilized when the system length
is shorter than a critical length , which is independent of the
resistivity . When is not too much longer than , the
growthrate is proportional to . When is sufficiently long,
the tearing mode scaling is recovered. The transition
from to occurs at a transition length
.Comment: Correct a typ
The black hole fundamental plane from a uniform sample of radio and X-ray emitting broad line AGNs
We derived the black hole fundamental plane relationship among the 1.4GHz
radio luminosity (L_r), 0.1-2.4keV X-ray luminosity (L_X), and black hole mass
(M) from a uniform broad line SDSS AGN sample including both radio loud and
radio quiet X-ray emitting sources. We found in our sample that the fundamental
plane relation has a very weak dependence on the black hole mass, and a tight
correlation also exists between the Eddington luminosity scaled X-ray and radio
luminosities for the radio quiet subsample. Additionally, we noticed that the
radio quiet and radio loud AGNs have different power-law slopes in the
radio--X-ray non-linear relationship. The radio loud sample displays a slope of
1.39, which seems consistent with the jet dominated X-ray model. However, it
may also be partly due to the relativistic beaming effect. For radio quiet
sample the slope of the radio--X-ray relationship is about 0.85, which is
possibly consistent with the theoretical prediction from the accretion flow
dominated X-ray model. We briefly discuss the reason why our derived
relationship is different from some previous works and expect the future
spectral studies in radio and X-ray bands on individual sources in our sample
to confirm our result.Comment: 23 pages, 7 figures, ApJ accepte
Entangling two superconducting LC coherent modes via a superconducting flux qubit
Based on a pure solid-state device consisting of two superconducting LC
circuits coupled to a superconducting flux qubit, we propose in this paper that
the maximally entangled coherent states of the two LC modes can be generated
for arbitrary coherent states through flux qubit controls.Comment: 5 pages, 2 figure
Visualizing the meaning of texts
We implemented SmartINFO, an experimental system for the visualization of the meaning of texts. SmartINFO consists of 4 modules: a universal grammar engine (UGE), an anaphora engine, a concept engine and a visualization engine. We discuss two methods of visualizing meanings of text. One approach is a word-centered approach and the other, a clausal-centered approach. © 2005 IEEE
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