119280925
General treatment for dark energy thermodynamics
In this work we discuss a general approach for the dark energy thermodynamics considering a varying equation of state parameter of the type $\ensuremath{\omega}(a)={\ensuremath{\omega}}_{0}+F(a)$ and taking into account the role of a nonzero chemical potential $\ensuremath{\mu}$. We derive generalized expressions for the entropy density, chemical potential, and dark energy temperature $T$ and use the positiveness of the entropy to impose thermodynamic bounds on the equation of state parameter $\ensuremath{\omega}(a)$. In particular, we find that a phantomlike behavior $\ensuremath{\omega}(a)l\ensuremath{-}1$ is allowed only when the chemical potential is a negative quantity ($\ensuremath{\mu}l0$).
119109342
Constraints on the exponential $f(R)$ model from latest Hubble parameter measurements
We investigate the viable exponential $f(R)$ gravity in the metric formalism with $f(R)=-\beta R_s (1-e^{-R/R_s})$. The latest sample of the Hubble parameter measurements with 23 data points is used to place bounds on this $f(R)$ model. A joint analysis is also performed with the luminosity distances of Type Ia supernovae and baryon acoustic oscillations in the clustering of galaxies, and the shift parameters from the cosmic microwave background measurements, which leads to $0.240 1.47$ at 1$\sigma$ confidence level. The evolutions of the deceleration parameter $q(z)$ and the effective equations of state $\omega_{de}^{eff}(z)$ and $\omega_{tot}^{eff}(z)$ are displayed. By taking the best-fit parameters as prior values, we work out the transition redshift (deceleration/acceleration) $z_T$ to be about 0.77. It turns out that the recent observations are still unable to distinguish the background dynamics in the $\Lambda$CDM and exponential $f(R)$ models.
119276084
Strong gravitational lensing of gravitational waves in Einstein Telescope
Gravitational wave experiments have entered a new stage which gets us closer to the opening a new observational window on the Universe. In particular, the Einstein Telescope (ET) is designed to have a fantastic sensitivity that will provide with tens or hundreds of thousand NS-NS inspiral events per year up to the redshift z = 2. Some of such events should be gravitationally lensed by intervening galaxies. We explore the prospects of observing gravitationally lensed inspiral NS-NS events in the Einstein telescope. Being conservative we consider the lens population of elliptical galaxies. It turns out that depending on the local insipral rate ET should detect from one per decade detection in the pessimistic case to a tens of detections per year for the most optimistic case. The detection of gravitationally lensed source in gravitational wave detectors would be an invaluable source of information concerning cosmography, complementary to standard ones (like supernovae or BAO) independent of the local cosmic distance ladder calibrations.
118606470
Constraints on a phiCDM model from strong gravitational lensing and updated Hubble parameter measurements
We constrain the scalar field dark energy model with an inverse power-law potential, i.e., V()  −α (α > 0), from a set of recent cosmological observations by compiling an updated sample of Hubble parameter measurements including 30 independent data points. Our results show that the constraining power of the updated sample of H(z) data with the HST prior on H0 is stronger than those of the SCP Union2 and Union2.1 compilations. A recent sample of strong gravitational lensing systems is also adopted to confine the model even though the results are not significant. A joint analysis of the strong gravitational lensing data with the more restrictive updated Hubble parameter measurements and the Type Ia supernovae data from SCP Union2 indicates that the recent observations still can not distinguish whether dark energy is a time-independent cosmological constant or a time-varying dynamical component.
119241739
Cosmic equation of state from combined angular diameter distances: Does the tension with luminosity distances exist?
Using a relatively complete observational data concerning four angular diameter distance (ADD) measurements and %synthetic combined SN+GRB observations representing current luminosity distance (LD) data, this paper investigates the %tension between compatibility of these two cosmological distances considering three classes of dark energy equation of state (EoS) reconstruction. In particular, we use strongly gravitationally lensed systems from various large systematic gravitational lens surveys and galaxy clusters, which yield the Hubble constant independent ratio between two angular diameter distances $D_{ls}/D_s$ data. Our results demonstrate that, with more general categories of standard ruler data, ADD and LD data are compatible at $1\sigma$ level. Secondly, we note that consistency between ADD and LD data %are blind is maintained irrespective of the EoS parameterizations: there is a good match between the universally explored CPL model and other formulations of cosmic equation of state. Especially for the truncated GEoS model with $\beta=-2$, the conclusions obtained with ADD and LD are almost the same. Finally, statistical analysis of generalized dark energy equation of state performed on four classes of ADD data provides stringent constraints on the EoS parameters $w_0$, $w_{\beta}$ and $\beta$, which suggest that dark energy was a subdominant component at early times. Moreover, the GEoS parametrization with $\beta\simeq 1$ seems to be a more favorable two-parameter model to characterize the cosmic equation of state, because the combined angular diameter distance data (SGL+CBF+BAO+WMAP9) provide the best-fit value $\beta=0.751^{+0.465}_{-0.480}$.
14585295
Quantum holonomy in three-dimensional general covariant field theory and the link invariant
We consider quantum holonomy of some three-dimensional general covariant non-Abelian field theory in the Landau gauge and confirm a previous result partially proven. We show that quantum holonomy retains metric independence after explicit gauge fixing and hence possesses the topological property of a link invariant. We examine the generalized quantum holonomy defined on a multicomponent link and discuss its relation to a polynomial for the link. {copyright} {ital 1997} {ital The American Physical Society}
121118981
Numerical study on quench process and protection of BES III superconducting detector magnet
A 3D quench simulation model was developed for the BES III magnet, which is a superconducting solenoid used in Beijing Spectrometer III (BES III) of Beijing Electron and Positron Collider II (BEPC II). The BES III magnet was inner winded with aluminum stabilized Rutherford cable and conduction-cooled with forced flow of two phase helium. Quench processes of the magnet under different protection techniques were simulated with the model. The minimum quench energy, the quench propagation velocity, the maximum temperature rise and the maximum voltage drop of the coil were analyzed. Protection capabilities of the different techniques were compared according to the simulation results, and the simulation results were compared with the experimental data. Recommendations to the protection of the detector magnets are presented.
120606363
Equivalence between stochastic quantization of a two-dimensional BF-type topological field theory and three-dimensional topological quantum field theory for a magnetic monopole
The stochastic quantization of a two-dimensional BF-type topological field model S= integral Sigma Tr phi F is performed. Its stochastic partition function is shown to be equivalent to that of three-dimensional topological quantum field theory for a magnetic monopole.
120066092
One-loop renormalization of Chern-Simons field theory in operator regularization
Operator regularization, together with the background field method, is used to calculate the one-loop renormalization constant of Chern-Simons field theory. The result shows the existence of the famous k shift, i.e. k to k+sgn(k)CV.
119352619
Decomposition of SU(N) connection and effective theory of SU(N) QCD
We give a general decomposition of SU(N) connection and derive a generalized Skyrme-Faddeev action as the effective action of SU(N) QCD in the Low energy limit. The result is obtained by separating the topological degrees which describes the non-Abelian monopoles from the dynamical degree of gauge potential, and integrating all the dynamical degrees of SU(N) QCD. (C) 2000 Published by Elsevier Science B.V.