36,979 research outputs found
Spin chain from marginally deformed AdS_3 x S^3
We derive a spin chain Hamiltonian from a fast spinning string in the
marginally deformed AdS(3)X S(3). This corresponds to a closed trajectory swept
out by the SU(2) or SL(2) spin vector on the surface of one-parameter deformed
two-sphere or hyperboloid in the background of anisotropic magnetic field
interaction. In the limit of small deformation, a class of general
Landau-Lifshitz equation with a nontrivial anisotropic matrix can be derived.Comment: 4 pages, 2 figures, revised for PR
Drag Force, Jet Quenching, and AdS/QCD
In this note, two important transport observables in the RHIC experiment,
relaxation time constant and jet quenching parameter, are calculated from an
AdS/QCD model. A quark moving in the viscous medium such as the
Quark-Gluon-Plasma is modelled by an open string whose end point travels on the
boundary of a deformed AdS_5 black hole. The correction introduced via the
deformed AdS_5 is believed to help us better understand the data which is
expected to be measured in the RHIC.Comment: 13 pages, 4 figures, revised for PRD. Some comments have been added
below Eq.(34) to avoid a misreading in comparison between our result and
CFT'
Price Determination in the Bottled Water Industry: A Case Study of Poland Spring
This paper analyzes the price of a single brand in the bottled water industry. We find that the brand's price is negatively related to its own share. We also find that price is positively related to the four firm concentration ratio in the carbonated segment, but unrelated in the noncarbonated segment.Demand and Price Analysis,
Detecting non-Abelian Statistics with Electronic Mach-Zehnder Interferometer
Fractionally charged quasiparticles in the quantum Hall state with filling
factor are expected to obey non-Abelian statistics. We demonstrate
that their statistics can be probed by transport measurements in an electronic
Mach-Zehnder interferometer. The tunneling current through the interferometer
exhibits a characteristic dependence on the magnetic flux and a non-analytic
dependence on the tunneling amplitudes which can be controlled by gate
voltages.Comment: 4 pages, 2 figures; Revtex; a discussion of the asymmetry of the I-V
curve adde
Fluctuation-dissipation theorem for chiral systems in non-equilibrium steady states
We consider a three-terminal system with a chiral edge channel connecting the
source and drain terminals. Charge can tunnel between the chiral edge and a
third terminal. The third terminal is maintained at a different temperature and
voltage than the source and drain. We prove a general relation for the current
noises detected in the drain and third terminal. It has the same structure as
an equilibrium fluctuation-dissipation relation with the nonlinear response in
place of the linear conductance. The result applies to a general chiral system
and can be useful for detecting "upstream" modes on quantum Hall edges.Comment: detailed proo
Remarks on the Theory of Cosmological Perturbation
It is shown that the power spectrum defined in the Synchronous Gauge can not
be directly used to calculate the predictions of cosmological models on the
large-scale structure of universe, which should be calculated directly by a
suitable gauge-invariant power spectrum or the power spectrum defined in the
Newtonian Gauge.Comment: 13 pages, 1 figure, minor changes, to be published in Chinese Physics
Letter
scalar glueball in finite-width Gaussian sum rules
Based on a semiclassical expansion for quantum chromodynamics in the
instanton liquid background, the correlation function of the scalar
glueball current is given, and the properties of the scalar glueball
are studied in the framework of Gaussian sum rules. Besides the pure classical
and quantum contributions, the contributions arising from the interactions
between the classical instanton fields and quantum gluons are come into play.
Instead of the usual zero-width approximation for the resonance, the
Breit-Wigner form for the spectral function of the finite-width resonance is
adopted. The family of the Gaussian sum rules for the scalar glueball in
quantum chromodynamics with and without light quarks is studied. A consistency
between the subtracted and unsubtracted sum rules is very well justified, and
the values of the decay width and the coupling to the corresponding current for
the resonance, in which the scalar glueball fraction is dominant, are
obtained.Comment: 18pages, 9figure
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