Temperature Dependence of Gluon and Quark Condensates as from Linear Confinement

The gluon and quark condensates and their temperature dependence are investigated within QCD premises. The input for the former is a gauge invariant $gg$ kernel made up of the direct (D), exchange (X) and contact(C) QCD interactions in the lowest order, but with the perturbative propagator $k^{-2}$ replaced by a `non-perturbative $k^{-4}$ form obtained via two differentiations: $\mu^2 \partial_m^2 (m^2+k^2)^{-1}$, ($\mu$ a scale parameter), and then setting $m=0$, to simulate linear confinement. Similarly for the input $q{\bar q}$ kernel the gluon propagator is replaced by the above $k^{-4}$ form. With these `linear' simulations, the respective condensates are obtained by `looping' up the gluon and quark lines in the standard manner. Using Dimensional regularization (DR), the necessary integrals yield the condensates plus temperature corrections, with a common scale parameter $\mu$ for both. For gluons the exact result is $$= {36\mu^4}\pi^{-3}\alpha_s(\mu^2)[2-\gamma - 4\pi^2 T^2/(3\mu^2)]$$. Evaluation of the quark condensate is preceded by an approximate solution of the SDE for the mass function $m(p)$, giving a recursive formula, with convergence achieved at the third iteration. Setting the scale parameter $\mu$ equal to the universal Regge slope $1 GeV^2$, the gluon and quark condensates at T=0 are found to be $0.586 Gev^4$ and $(240-260 MeV)^3$ respectively, in fair accord with QCD sum rule values. Next, the temperature corrections (of order $-T^2$ for both condensates) is determined via finite-temperature field theory a la Matsubara. Keywords: Gluon Condensate, mass tensor, gauge invariance, linear confinement, finite-temperature, contour-closing. PACS: 11.15.Tk ; 12.38.Lg ; 13.20.CzComment: 13 pages (LaTeX) including 2 figure

Edge and bulk merons in double quantum dots with spontaneous interlayer phase coherence

We have investigated nucleation of merons in double quantum dots when a lateral distortion with a reflection symmetry is present in the confinement potential. We find that merons can nucleate both inside and at the edge of the dots. In addition to these merons, our results show that electron density modulations can be also present inside the dots. An edge meron appears to have approximately a half integer winding number.Comment: 5 pages, 4 figures, Proceedings of 17th International Conference on High Magnetic Fields in Semiconductor Physic

Quantum fluctuations of Cosmological Perturbations in Generalized Gravity

Recently, we presented a unified way of analysing classical cosmological perturbation in generalized gravity theories. In this paper, we derive the perturbation spectrums generated from quantum fluctuations again in unified forms. We consider a situation where an accelerated expansion phase of the early universe is realized in a particular generic phase of the generalized gravity. We take the perturbative semiclassical approximation which treats the perturbed parts of the metric and matter fields as quantum mechanical operators. Our generic results include the conventional power-law and exponential inflations in Einstein's gravity as special cases.Comment: 5 pages, revtex, no figure

Unified Analysis of Cosmological Perturbations in Generalized Gravity

In a class of generalized Einstein's gravity theories we derive the equations and general asymptotic solutions describing the evolution of the perturbed universe in unified forms. Our gravity theory considers general couplings between the scalar field and the scalar curvature in the Lagrangian, thus includes broad classes of generalized gravity theories resulting from recent attempts for the unification. We analyze both the scalar-type mode and the gravitational wave in analogous ways. For both modes the large scale evolutions are characterized by the same conserved quantities which are valid in the Einstein's gravity. This unified and simple treatment is possible due to our proper choice of the gauges, or equivalently gauge invariant combinations.Comment: 4 pages, revtex, no figure

Stellar structures in the outer regions of M33

We present Subaru/Suprime-Cam deep V and I imaging of seven fields in the outer regions of M33. Our aim is to search for stellar structures corresponding to extended HI clouds found in a recent 21-cm survey of the galaxy. Three fields probe a large HI complex to the southeastern (SE) side of the galaxy. An additional three fields cover the northwestern (NW) side of the galaxy along the HI warp. A final target field was chosen further north, at a projected distance of approximately 25 kpc, to study part of the large stellar plume recently discovered around M33. We analyse the stellar population at R > 10 kpc by means of V, I colour magnitude diagrams reaching the red clump. Evolved stellar populations are found in all fields out to 120' (~ 30 kpc), while a diffuse population of young stars (~ 200 Myr) is detected out to a galactocentric radius of 15 kpc. The mean metallicity in the southern fields remains approximately constant at [M/H] = -0.7 beyond the edge of the optical disc, from 40' out to 80'. Along the northern fields probing the outer \hi disc, we also find a metallicity of [M/H] = -0.7 between 35' and 70' from the centre, which decreases to [M/H] = -1.0 at larger angular radii out to 120'. In the northernmost field, outside the disc extent, the stellar population of the large stellar feature possibly related to a M33-M31 interaction is on average more metal-poor ([M/H] = -1.3) and older (> 6 Gyr). An exponential disc with a large scale-length (~ 7 kpc) fits well the average distribution of stars detected in both the SE and NW regions from a galactocentric distance of 11 kpc out to 30 kpc. The stellar distribution at large radii is disturbed and, although there is no clear correlation between the stellar substructures and the location of the HI clouds, this gives evidence for tidal interaction or accretion events.Comment: 13 pages, 13 figures. Accepted for publications in Astronomy and Astrophysics; minor revisions of the tex

Relativistic Hydrodynamic Cosmological Perturbations

Relativistic cosmological perturbation analyses can be made based on several different fundamental gauge conditions. In the pressureless limit the variables in certain gauge conditions show the correct Newtonian behaviors. Considering the general curvature ($K$) and the cosmological constant ($\Lambda$) in the background medium, the perturbed density in the comoving gauge, and the perturbed velocity and the perturbed potential in the zero-shear gauge show the same behavior as the Newtonian ones in general scales. In the first part, we elaborate these Newtonian correspondences. In the second part, using the identified gauge-invariant variables with correct Newtonian correspondences, we present the relativistic results with general pressures in the background and perturbation. We present the general super-sound-horizon scale solutions of the above mentioned variables valid for general $K$, $\Lambda$, and generally evolving equation of state. We show that, for vanishing $K$, the super-sound-horizon scale evolution is characterised by a conserved variable which is the perturbed three-space curvature in the comoving gauge. We also present equations for the multi-component hydrodynamic situation and for the rotation and gravitational wave.Comment: 16 pages, no figure, To appear in Gen. Rel. Gra

Mounting technique for pressure transducers minimizes measurement interferences

Miniaturized transducers are fabricated from commercially available four-arm semiconductor gages; transducers are connected as bridge circuit and mounted on internal face of small diaphragm. Jacket made of conductive plastic may be needed to avoid buildup or static charges