120668478
An accelerated universe from Brans-Dicke theory in the Einstein frame
The current acceleration of the universe is not consistent with the theory of general relativity (GR). The substitutes of GR have been studied widely. One of them is the Brans-Dicke (BD) theory. Thereinto, most studies of BD theory are in the frame of Jordan representation. In this paper we investigate the accelerating cosmology from BD theory in the other frame, i.e. in the Einstein frame, where it indicates the interaction between the matter and the BD scalar field. We apply the Markov Chain Monte Carlo method to study the cosmic constraints on BD theory according to the current experiment data from the kinematical observations: the Union2 dataset of type supernovae Ia (SNIa) and the observational Hubble data (OHD), and the dynamical observations: the baryon acoustic oscillation (BAO), the cosmic microwave background (CMB) data, and the cluster X-ray gas mass fraction. It is shown that an expanded universe from deceleration to acceleration is given in this theory. And the constraint results on BD model parameters are β = −0.0067(±0.2268)−0.2372−0.4407+0.2395+0.4168, γ = 0.0237(±0.0342)−0.0329−0.0647+0.0326+0.0715, ε = −0.0063(±0.0073)−0.0073−0.0130+0.0072+0.0158; and the constraints values of some correlative cosmological parameters are the dimensionless matter density Ω0m = 0.2853(±0.0132)−0.0133−0.0247+0.0132+0.0262, the cosmic age = 13.5699(±0.2398)−0.2374−0.4568+0.2371+0.4806 Gyr, and the current Hubble parameter H0 = 70.2623(±1.2695)−1.2675−2.5150+1.2749+2.4532.
119216015
More on QCD ghost dark energy
The difference between the vacuum energy of quantum fields in Minkowski space and in a Friedmann-Robertson-Walker universe might be related to the observed dark energy. The vacuum energy of the Veneziano ghost field introduced to solve the U(1)(A) problem in QCD is of the form H + O(H-2). Based on this, we study the dynamical evolution of a phenomenological dark energy model whose energy density is of the form alpha H + beta H-2. In this model, the universe approaches a de Sitter phase at late times. We fit the model with current observational data, including SnIa, BAO, CMB, BBN, the Hubble parameter, and the growth rate of matter perturbation. It shows that the universe begins to accelerate at redshift z similar to 0.75, and this model is consistent with current data. In particular, this model fits the data of the growth factor well as the Lambda CDM model.
204012276
Evolution of Holographic Dark Energy in Interacting Modified Chaplygin Gas Model
We investigate the modified Chaplygin gas (MCG) with interaction between holographic dark energy proposed by Li and dark matter. In this model, evolution of the universe is described in detail, which is from deceleration to acceleration. Specifically, the evolutions of related cosmological quantities such as density parameter, the equation of state of holographic dark energy, deceleration parameter and transition redshift are discussed. Moreover, we also give their present values which are consistent with the lately observations. Furthermore, the results given by us show such a model can accommodate a transition of the dark energy from a normal state wX > – 1 to wX < – 1 phantom regimes.
118601675
Holographic p-wave superfluid
In the probe limit, we numerically construct a holographic p-wave superfluid model in the 4D and 5D AdS black holes coupled to a Maxwell-complex vector field. 
We find that, for the condensate with the fixed superfluid velocity, the results are similar to the s-wave cases in both 4D and 5D spacetimes. In particular, "The Cave of Winds" and the phase transition always being the second order take place in the 5D case. Moreover, we find the second-first order translating point $\frac{S_y}{\mu}$ increases with the mass squared. Furthermore, for the supercurrent with the fixed temperature, the results agree with the GL prediction near the critical temperature. In addition, this complex vector superfluid model is still a generalization of the SU(2) superfluid model, and also provides a holographic realization of the $He_3$ superfluid system.
121684801
THE VARIABLE GENERALIZED CHAPLYGIN GAS MODEL WITH INTERACTION
In this paper a variable generalized Chaplygin gas (VGCG) proposal for unification of dark matter and dark energy is considered, in which dark energy interacts with dark matter. The equation of state of the VGCG is given by p = -A0a-n/ρα, where a is the scale factor. By calculations some cosmological quantities such as density parameters of baryons, dark matter and dark energy as well as the deceleration parameter are all obtained. Furthermore, the transition from deceleration to acceleration is described and the interaction between dark energy and dark matter is considered in this model. We find the behavior of VGCG is similar to dust-like matter at early times and will be quintessence or phantom at late stage. In addition the evolution trajectory of the VGCG model in the statefinder parameter s-r plane is plotted and the discrimination between this scenario and the generalized Chaplygin gas (GCG) model is illustrated.
122140692
Constraints of energy conditions and DK instability criterion on f(R, Lm) gravity models
Some properties of f(R, Lm) gravity are studied in this paper. Concretely, the energy conditions and the Dolgov–Kawasaki (DK) instability criterion in f(R, Lm) gravity are obtained, which are quite general and can degenerate to the ones in General Relativity (GR) and pure f(R) gravity with non-coupling and non-minimal coupling as well as in [J. Wang and K. Liao, Class. Quantum Grav. 29, 215016 (2012)] as special cases. Furthermore, in order to get some insight on the meaning of the energy conditions and the DK instability criterion, we apply them to the concrete type of f(R, Lm) gravity models and the corresponding constraints on the models are given.
18736676
Yano-Koonin-Podgoretskii parametrization of the HBT correlator: A Numerical study
The Yano-Koonin-Podgoretski˘ ı (YKP) parametrisation of Hanbury-Brown/Twiss (HBT) two-particle correlation functions opens new strategies for extracting the emission duration and testing the longitudinal expansion in heavy-ion collisions. Based on the recently derived model-independent expressions , we present a detailed parameter study of the YKP fit parameters for a hydrodynamic finite expanding source model of heavy-ion collisions. Our study supports the clean spatio-temporal interpretation of the three YKP radius parameters as longitudinal extension, transverse extension and emission duration of the source in the YKP Lorentz frame. This frame is specified by the fourth fit parameter, the Yano-Koonin velocity which describes to a good approximation the velocity of the fluid element with highest emissivity and allows to test for the longitudinal expansion of the source. Deviations from this interpretation of the YKP parameters are quantitatively discussed and found to be generically small.
119102176
Kaon Interferometry
Two-kaon and two-pion correlation functions for an expanding thermalized source are compared. In the Yano-Koonin-Podgoretskii parametrization of the correlation function, the HBT radius parameters are shown to obey M_\bot- scaling in the absence of collective transverse flow. This scaling is broken by transverse flow. An accurate comparison of pion and kaon correlations can thus resolve issue whether the observed M_\bot-dependence of the transverse radius parameter is due to transverse collective flow or other transverse gradients. Effects from resonance decays are shortly discussed.
118408012
Measurement of Cosmic Ray Flux in China JinPing underground Laboratory
China JinPing underground Laboratory (CJPL) is the deepest underground laboratory presently running in the world. In such a deep underground laboratory, the cosmic ray flux is a very important and necessary parameter for rare event experiments. A plastic scintillator telescope system has been set up to measure the cosmic ray flux. The performance of the telescope system has been studied using the cosmic ray on the ground laboratory near CJPL. Based on the underground experimental data taken from November 2010 to December 2011 in CJPL, which has effective live time of 171 days, the cosmic ray muon flux in CJPL is measured to be (2.0+-0.4)*10^(-10)/(cm^2)/(s). The ultra-low cosmic ray background guarantees CJPL's ideal environment for dark matter experiment.
117033219
Critical behavior of Binder ratios and ratios of higher order cumulants of conserved charges in QCD deconfinement phase transition
Binder liked ratios of baryon number are firstly suggested in relativistic heavy ion collisions. Using 3D-Ising model, the critical behavior of Binder ratios and ratios of high order cumulants of order parameter are fully presented. Binder ratio is shown to be a step function of temperature. The critical point is the intersection of the ratios of different system sizes between two platforms. From low to high temperature through the critical point, the ratios of third order cumulants change their values from negative to positive in a valley shape, and ratios of fourth order cumulants oscillate around zero. The normalized ratios, like the Skewness and Kurtosis, do not diverge with correlation length, in contrary with corresponding cumulants. Applications of these characters in search critical point in relativistic heavy ion collisions are discussed.
17896194
On the Intermittency and Chaos in High Energy Collisions
It is shown that an event sample from the Monte Carlo simulation of a random cascading \alpha model with fixed dynamical fluctuation strength is intermittent but not chaotic, while the variance of dynamical fluctuation strength in different events will result in both the intermittency and the chaotic behavior. This shows that fractality and chaoticity are two connected but different features of non-linear dynamics in high energy collisions.