118375005
Observing various phase transitions in the holographic model of superfluidity
We study the gravity duals of supercurrent solutions in the AdS black hole background with general phase structure to describe both the first and the second order phase transitions at finite temperature in strongly interacting systems. We argue that the conductivity and the pair susceptibility can be possible phenomenological indications to distinguish the order of phase transitions. We extend our discussion to the AdS soliton configuration. Different from the black hole spacetime, in the probe limit the first order phase transition cannot be brought by introducing the spatial component of the vector potential of the gauge field in the AdS soliton background.
118198563
Dark Energy: Relating the Evolutions of the Universe from the Past to the Future
Using the evolution history of the universe, one can make constraint on the parameter space of dynamic dark energy models. We discuss two different parameterized dark energy models. Our results further restrict the combined constraints obtained from supernova and the first-year Wilkinson-microwave-anisotropy-probe observations. From the allowed parameter space, it is found that our universe will experience an eternal acceleration. We also estimate the bound on the physically relevant regions both in the re-inflationary and inflationary phases.
118997018
Probing the curvature of the Universe from supernova measurement
We study the possibility to probe the spatial geometry of the Universe by supernova measurement. We illustrate with an accelerating universe model with infinite-volume extra dimensions, for which the 1σ level supernova results indicate that the Universe is closed.
124897627
Different Quantum Entropies for Two Kinds of Extreme Two-Dimensional Lowe–Strominger Black Holes*
It is shown that both the classical entropy of two-dimensional extremal Lowe–Strominger black hole and the quantum entropy of the scalar field in the background of this black hole are different by using Hawking's treatment as wel as Zaslavskii's treatment respectively. This result supports our previous suggestion that there are two kinds of extreme black holes in the nature. A new divergent term emerges in the quantum entropy in Zaslavskii's treatment and its physical meaning has been discussed.
119186601
Various types of phase transitions in the AdS soliton background
We study the basic holographic insulator and superconductor phase transition in the AdS soliton background by generalizing the spontaneous breaking of a global U(1) symmetry to occur via Stuckelberg mechanism. We construct the soliton solutions with backreaction and examine the effects of the backreaction on the condensation of the scalar hair in the generalized Stuckelberg Lagrangian. We disclose rich physics in various phase transitions. In addition to the AdS soliton configuration, we also examine the property of the phase transition in the AdS black hole background.
30079794
Stability of the event horizon in (2+1)-dimensional black holes.
111424651
Ion Transportation Study for Thick Gas Electron Multipliers
Ion back flow(IBF) is defined as the ions that are generated during multiplication in a thick-gas-electron-multiplier (THGEM) detector flow along the electric field. In order to suppress the IBF effect, we study ion transportation for THGEMs with various high voltages and geometrical parameters. By measuring the currents of all the electrodes of the THGEMs, the effective gain and ion back flow ratio are calculated. The measurement and simulation results reveal that with a staggered triple THGEM configuration, ion back flow can be suppressed to 1% with a proper working high voltage. The gain of the staggered configuration is less than that of the aligned configuration by 5% under the same high voltage condition. The design and the results are presented.
16859067
THE MASS FUNCTION OF DARK MATTER HALOES IN A COSMOLOGICAL MODEL WITH A RUNNING PRIMORDIAL POWER SPECTRUM
We present the first study on the mass functions of Jenkins et al. (J01) and an estimate of their corresponding largest virialized dark halos in the Universe for a variety of dark-energy cosmological models with a running spectral index. Compared with the PL–CDM model, the RSI–CDM model can raise the mass abundance of dark halos for small mass halos at lower redshifts, but it is not apparent on scales of massive mass halos. Particularly, this discrepancy increases largely with the decrease of redshift, and the RSI–CDM model can suppress the mass abundance on any scale of halo masses at higher redshift. As for the largest mass of virialized halos, the spatially flat ΛCDM models give more massive mass of virialized objects than other models for both of PL–CDM and RSI–CDM power spectral indexs, and the RSI–CDM model can enhance the mass of largest virialized halos for all of models considered in this paper. So we probably distinguish the PL–CDM and RSI–CDM models by the largest virialized halos in the future...
120034276
de Broglie–Bohm interpretation for wave function of a toroidal black hole
The mass function of a toroidal black hole as a dynamical variable is given by using Kuchar’s approach. Then the toroidal black hole is investigated by using the de Broglie–Bohm approach, and its quantum potential and quantum trajectories are obtained. In our process the vector potential of the electromagnetic field in the toroidal black hole is treated as a canonical variable.
119774346
Heavy-element abundances and massive star formation
We investigate the observational consequences that arise for the heavy-element abundances in normal spiral galaxies from variations in the initial mass function (IMF). In particular, we calculate the oxygen yield for a given IMF, using the most recent calculations of supernova nucleosynthesis. Assuming instantaneous recycling of oxygen, we calculate the resultant oxygen abundance. The predicted and observed oxygen abundances in our Galaxy are compared, and we find that the overall abundance is well explained by the IMF determined in the solar neighborhood
126084815
Entropy of quantum field in toroidal black hole without brick wall
The calculation of the brick-wall model gives the entropy as two terms: one is proportional to the horizon area and the other is a constant. Then they renormalized the entropy by introducing the Newton’s constant and the entropy correction arising from the higher curvature effective gravitational action. Finally, they got the renormalized entropy whose leading term is proportional to the horizon area of the black hole and the others is precisely the one-loop correction arising from the higher curvature terms of the gravitational action. Their work confirmed the suggestion by Susskind and Uglum [25] that these divergences have the correct form to be absorbed in the Bekenstein–Hawking formula as a renormalization of Newton’s constant.