Hole Phase Research Articles

Thermal analysis of gravitational decoupling black hole solution

In this work, we examine the thermodynamic properties of the hairy black holes that develop when the Reissner–Nordström geometry is applied to the gravitational decoupling method. Gibbs free energy and energy emission are also examined in our investigation. We compute several parameters to evaluate the local and global thermodynamic stability, including the Hawking temperature, geometric mass, and heat capacity. The first law of thermodynamics calculates the black hole's temperature and assesses the energy emission rate. We investigate the black hole's phase transition behavior by calculating the Gibbs free energy, paying particular attention to the swallowing tails.

Depletion Type Organic Electrochemical Transistors and the Gradual Channel Approximation

AbstractThe gradual channel approximation forms the foundation for the analysis of field‐effect transistors. It has been used to discuss transistors that are not necessarily based on the field‐effect as well, such as the organic electrochemical transistor (OECT). Here, the applicability of the gradual channel approximation for OECTs is studied by a 2D drift‐diffusion model. It is found that OECT switching can be described by two separate effects—a doping/dedoping mechanism and the formation of an electrostatic double layer at the interface between the mixed conductor and the electrolyte. The balance between these two mechanisms is determined by the morphology of the mixed conductor, in particular the question if ions move in the same phase and electric potential as the holes, or if separate ion and hole phases are formed. It is argued that the gradual channel approximation can only be used to describe electrostatic switching at the mixed conductor/electrolyte interface (the two‐phase model), but cannot be employed to analyze devices operating on a doping/de‐doping mechanism (the one‐phase model).

Critical Phenomena of Charged AdS Black Holes in Rastall Gravity

We construct analytical charged anti-de Sitter (AdS) black holes surrounded by perfect fluids in four dimensional Rastall gravity. Then, we discuss the thermodynamics and phase transitions of charged AdS black holes immersed in regular matter like dust and radiation, or exotic matter like quintessence, ΛCDM type, and phantom fields. Surrounded by phantom field, the charged AdS black hole demonstrates a new phenomenon of reentrant phase transition (RPT) when the parameters Q, Np, and ψ satisfy some certain condition, along with the usual small/large black hole (SBH/LBH) phase transition for the surrounding dust, radiation, quintessence, and cosmological constant fields.

Phase Structure and Quasinormal Modes of AdS Black Holes in Rastall Theory

We discuss the P−V criticality and phase transition in the extended phase space of anti-de Sitter(AdS) black holes in four-dimensional Rastall theory and recover the Van der Waals (VdW) analogy of small/large black hole (SBH/LBH) phase transition when the parameters ωs and ψ satisfy some certain conditions. Later, we further explore the quasinormal modes (QNMs) of massless scalar perturbations to probe the SBH/LBH phase transition. It is found that it can be detected near the critical point, where the slopes of the QNM frequencies change drastically in small and large black holes.

A discrete oppositional multi-verse optimization algorithm for multi-skill resource constrained project scheduling problem

In this paper, a discrete oppositional multi-verse optimization (DOMVO) algorithm is proposed to address multi-skill resource constrained project scheduling problem (MS-RCPSP). Firstly, the black/white holes phase in DOMVO algorithm is designed by integrating path relinking technique. Secondly, two improved path relinking methods are presented and embedded into the proposed scheme to enhance search abilities. Thirdly, the opposition-based learning (OBL) method is employed as a hybrid strategy to improve the quality of solutions. Moreover, a repair-based decoding scheme is developed to generate schedules more efficiently. Additionally, the design-of-experiment (DOE) method is carried out to investigate the influence of parameters setting. Finally, the effectiveness of DOMVO is evaluated on the intelligent multi-objective project scheduling environment (iMOPSE) benchmark dataset and the computational comparisons indicate the superiority of the proposed DOMVO over the state-of-the-art algorithms in solving MS-RCPSP.

Real time quantum gravity dynamics from classical statistical Yang-Mills simulations

We perform microcanonical classical statistical lattice simulations of SU(N) Yang-Mills theory with eight scalars on a circle. Measuring the eigenvalue distribution of the spatial Wilson loop we find two distinct phases depending on the total energy and circle radius, which we tentatively interpret as corresponding to black hole and black string phases in a dual gravity picture. We proceed to study quenches by first preparing the system in one phase, rapidly changing the total energy, and monitoring the real-time system response. We observe that the system relaxes to the equilibrium phase corresponding to the new energy, in the process exhibiting characteristic damped oscillations. We interpret this as the topology change from black hole to black string configurations, with damped oscillations corresponding to quasi-normal mode ringing of the black hole/black string final state. This would suggest that α′ corrections alone can resolve the singularity associated with the topology change. We extract the real and imaginary part of the lowest-lying presumptive quasinormal mode as a function of energy and N.

Wilson loop's phase transition probed by non-local observable

In order to give further insights into the holographic Van der Waals phase transition, it would be of great interest to investigate the behavior of Wilson loop across the holographic phase transition for a higher dimensional hairy black hole. We offer a possibility to proceed with a numerical calculation in order to discussion on the hairy black hole's phase transition, and show that Wilson loop can serve as a probe to detect a phase structure of the black hole. Furthermore, for a first order phase transition, we calculate numerically the Maxwell's equal area construction; and for a second order phase transition, we also study the critical exponent in order to characterize the Wilson loop's phase transition.

Holographic research on phase transitions for a five dimensional AdS black hole with conformally coupled scalar hair

Abstract In the framework of holography, we survey the phase structure for a higher dimensional hairy black hole including the effects of the scalar field hair. It is worth emphasizing that, not only black hole entropy, but also entanglement entropy and two point correlation function exhibit the Van der Waals-like phase transition in a fixed scalar charge ensemble. Furthermore, by making use of numerical computation, we show that the Maxwell's equal area law is valid for the first order phase transition. In addition, we also discuss how the hair parameter affects the black hole's phase transition.

Influence of Gauss-Bonnet Coupling Parameter on the Thermodynamic Properties of Einstein-Gauss-Bonnet and Einstein-Yang-Mills-Gauss-Bonnet Black Holes

This paper deals in the thermodynamic properties of Einstein-Gauss-Bonnet and Einstein-Yang-Mills-Gauss-Bonnet black holes. It exhibits the various stable and unstable phases of the black holes in these two modified gravity theories. In the first section, that reveals the various aspects of Einstein-Gauss-Bonnet black holes, we chose to study the changes in the Hawking Temperature with variations in the radius of event horizon (r) and charge (Q); and tried to justify them physically. Secondly in case of Einstein-Yang-Mills-Gauss-Bonnet black holes, we have attempted to compare the changes in the various thermodynamic parameters with varying r and Q; with the Einstein-Gauss-Bonnet black holes at a macroscopic level. Here we have considered the Yang Mills tensor, electromagnetic Lagrangian added to the action integrand. Again this very work deals in drawing out the similarities between these two types of black holes, thereby throwing some light on the aspect of black hole stability. Later we have also introspected the effects of the Gauss-Bonnet coupling parameter α, whose function (6αr), is added as a correction term to the black hole entropy. We have especially focused on what changes does it have upon the nature of the plots as to whether it enhances or reduces the effect of Q on the behavior of the curves. Finally this paper has also kept an eye at estimating the stability domains of the black holes described in these two gravity theories.

Symmetry in the superconducting, insulating and metallic phases of doped cuprates

Abstract A semiempirical model is proposed which accounts in a simple way for the insulating, superconducting and metallic phases of electron and hole doped cuprate layers.

Black hole emissions and phase transitions

The nonthermal emission of a rotating black hole is related to the inner horizon of the hole. The transition from the Kerr black hole state to the naked singularity state is considered as a phase transition. An arrangement of the energetics of Kerr black holes into a two-phase thermodynamics is suggested.