49 research outputs found
Quantization of Neveu-Schwarz-Ramond Superstring Model in 10+2-dimensional Spacetime
We construct a Neveu-Schwarz-Ramond superstring model which is invariant
under supersymmetric U(1)_V * U(1)_A gauge transformations as well as the
super-general coordinate, the super local Lorentz and the super-Weyl
transformations on the string world-sheet. We quantize the superstring model by
covariant BRST formulation a la Batalin and Vilkovisky and noncovariant
light-cone gauge formulation. Upon the quantizations the model turns out to be
formulated consistently in 10+2-dimensional background spacetime involving two
time dimensions.Comment: 1+61 pages, no figures, LaTe
Magnetic conductivity and Chern-Simons Term in Holographic Hydrodynamics of Charged AdS Black Hole
We study the effects of the Chern-Simons term in the hydrodynamics of the
five-dimensional Reissner-Nordstrom-AdS background. We work out the decoupling
problem of the equations of motion and calculate the retarded Green functions
explicitly. We then find that the Chern-Simons term induces the magnetic
conductivity caused by the anomaly effect. It is increasing function of
temperature running from a non-zero value at zero temperature to the twice the
value at infinite temperature.Comment: 19 pages, 2 figures; v2 discussion on classification of perturbation
fields based on helicity base, third order in dispersion relation and more
discussion on magnetic conductivity are added, some typos are corrected and
references are added; v3 published versio
Quark Number Susceptibility with Finite Quark Mass in Holographic QCD
We study the effect of a finite quark mass on the quark number susceptibility
in the framework of holographic QCD. We work in a bottom-up model with a
deformed AdS black hole and D3/D7 model to calculate the quark number
susceptibility at finite temperature with/without a finite quark chemical
potential. As expected the finite quark mass suppresses the quark number
susceptibility. We find that at high temperatures MeV the quark
number susceptibility of light quarks and heavy quarks are almost equal in the
bottom-up model. This indicates that the heavy quark like charm contribution to
thermodynamics of a QCD-like system may start to become significant at
temperatures MeV. In D3/D7 model, we focus on the competition
between the quark chemical potential, which enhances the quark number
susceptibility, and the quark mass that suppresses the susceptibility. We
observe that depending on the relative values of the quark mass and the quark
chemical potential, the quark number susceptibility shows a diverging or
converging behavior. We also calculate the chiral susceptibility in D3/D7 model
to support the observation made with the quark number susceptibility.Comment: 16 pages, 3 figure