118569311
Modified f(G) gravity models with curvature–matter coupling
A modified f(G) gravity model with coupling between matter and geometry is proposed, which is described by the product of the Lagrange density of the matter and an arbitrary function of the Gauss–Bonnet term. The field equations and the equations of motion corresponding to this model show the non-conservation of the energy-momentum tensor, the presence of an extra force acting on test particles and non-geodesic motion. Moreover, the energy conditions and the stability criterion at the de Sitter point in modified f(G) gravity models with curvature–matter coupling are derived, which can degenerate to the well-known energy conditions in general relativity. Furthermore, in order to get some insight in the meaning of these energy conditions, we apply them to the specific models of f(G) gravity and the corresponding constraints on the models are given. In addition, the conditions and the candidate for late-time cosmic accelerated expansion in modified f(G) gravity are studied by means of conditions of power-law expansion and the equation of state of matter ω smaller than $-\frac{1}{3}$.
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.
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.
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.
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.
118647633
Trace initial interaction from final state observable in relativistic heavy ion collisions
sNN = 200 GeV by using the Monte Carlo models RQMD with hadron re-scattering and AMPT with and without string melting, we observe that the correlation patterns change gradually from out-of-plane preferential one to in-plane preferential one when the centrality of collision shifts from central to peripheral, meanwhile the anisotropic collective flow v2 keeps positive in all cases. This regularity is found to be model and collision energy independent. The physics behind the two opposite trends of correlation patterns, in particular, the presence of out-of-plane correlation patterns at RHIC energy, are discussed.
8561645
Parton branching in the color mutation model
The soft production problem in hadronic collisions as described in the eikonal color mutation branching model is improved in the way that the initial parton distribution is treated. Furry branching of the partons is considered as a means of describing the nonperturbative process of parton reproduction in the soft interaction. The values of all the moments, {l_angle}n{r_angle} and C{sub q}, for q=2,{hor_ellipsis},5, as well as their energy dependences, can be correctly determined by the use of only two parameters. {copyright} {ital 1999} {ital The American Physical Society}
122405855
Erraticity analysis of multiparticle production in π+p and K+p collisions at 250 GeV/c
Abstract The erraticity behavior of multiparticle production is analyzed in π + p and K + p collisions at 250 GeV/ c . It is demonstrated that, for these low-multiplicity final states, the erraticity measure based on event-to-event fluctuation of factorial moments is dominated by statistical fluctuations.
53370258
Two-particle azimuthal angle correlations and azimuthal charge balance function in relativistic heavy ion collisions
The two-particle azimuthal angle correlation (TPAC) and azimuthal charge balance function (ACBF) are used to study the anisotropic expansion in relativistic heavy ion collisions. It is demonstrated by the relativistic quantum molecular dynamics (RQMD) model and a multi-phase transport (AMPT) model that the small-angle correlation in TPAC indeed presents anisotropic expansion, and the large-angle (or back-to-back) correlation is mainly due to global momentum conservations. The AMPT model reproduces the observed TPAC, but the RQMD model fails to reproduce the strong correlations in both small and large azimuthal angles. The width of ACBF from RQMD and AMPT models decreases from peripheral to central collisions, consistent with experimental data, but in contrast to the expectation from thermal model calculations. The ACBF is insensitive to anisotropic expansion. It is a probe for the mechanism of hadronization, similar to the charge balance function in rapidity.
124740049
Longitudinal boost invariance of the charge balance function in hadron-hadron and nucleus-nucleus collisions
Using Monte Carlo generators of the PYTHIA model for hadron-hadron collisions and a multiphase transport (AMPT) model for nucleus-nucleus collisions, the longitudinal boost invariance of charge balance function and its transverse-momentum dependence are carefully studied. It shows that the charge balance function is boost invariant in both p+p and Au+Au collisions in these two models, consistent with experimental data. The balance function properly scaled by the width of the pseudorapidity window is independent of the position or the size of the window and is corresponding to the balance function of the whole pseudorapidity range. This longitudinal property of balance function also holds for particles in small transverse-momentum ranges in the PYTHIA and the AMPT default models, but is violated in the AMPT with string melting. The physical origin of the results is discussed.