A5100619575- Black Holes and Theoretical Physics
- Cosmology and Gravitation Theories
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Quantum Electrodynamics and Casimir Effect
- Differential Equations and Numerical Methods
- Stochastic processes and financial applications
- Noncommutative and Quantum Gravity Theories
- Gamma-ray bursts and supernovae
- Nonlinear Waves and Solitons
- Fractional Differential Equations Solutions
- Fluid Dynamics and Turbulent Flows
- Fuel Cells and Related Materials
- Electrocatalysts for Energy Conversion
- advanced mathematical theories
- Magnetic properties of thin films
- Power Systems and Renewable Energy
- Quantum many-body systems
- Financial Markets and Investment Strategies
- Magnetic Properties and Synthesis of Ferrites
- Nonlinear Differential Equations Analysis
- Magnetic Properties of Alloys
- Advancements in Solid Oxide Fuel Cells
- Advanced Mathematical Modeling in Engineering
- Rough Sets and Fuzzy Logic
Xiangtan University
2021-2024
North China Electric Power University
2024
University of Science and Technology Beijing
2024
Hunan Normal University
2009-2023
Xiamen University
2022
Anhui University of Finance and Economics
2021
University of Aveiro
2012-2016
Changsha Normal University
2010
The Ohio State University
1994
Abstract The single‐phase oxides with elemental complexity and compositional diversity, usually named high entropy oxides, feature homogeneously dispersed multi‐metallic elements in equiatomic concentration. unusual properties of endow their potential application clean‐energy‐related electrocatalysis. However, the possible fundamental relationship between configuration underlying catalytic mechanism is still not well understood established. Herein, a perovskite cobaltate consisting five...
Scalar and gravitational perturbations on Kerr--anti--de Sitter (Kerr-AdS) black holes have been addressed in the literature shown to exhibit a rich phenomenology. In this paper, we complete analysis of bosonic fields background by studying Maxwell perturbations, focusing superradiant instabilities vector clouds. For purpose, solve Teukolsky equations numerically, imposing boundary conditions proposed [1] for radial equation. As found therein, two Robin can be imposed Kerr-AdS holes, one...
We have studied stationary clouds of massive scalar fields around a rotating BTZ-like black hole in the Einstein-bumblebee gravity, by imposing Robin type boundary conditions at AdS boundary. establish, scanning parameter space, existence \textit{fundamental} ($i.e.$, overtone number $n=0$). In particular, we observe that Lorentz symmetry breaking $s$ and quantum $k$ play an opposite role determining clouds, which indicates \textit{degenerate} clouds. To illustrate fact may only be supported...
Massive scalar test fields around Kerr black holes can form quasibound states with complex frequencies. Some of these decay in time, but some others---in the superradiant regime---grow, causing a instability. Precisely at threshold between decaying and growing modes, there exist bound real frequency, known as clouds. Fully nonlinear counterparts clouds have been shown to yield hair. Here, we consider massive, (electrically) charged, scalar, Proca on background Reissner-Nordstr\"om holes. By...
We investigate the superradiant instability for a charged scalar field in $D$-dimensional small Reissner--Nordstr\"om--anti-de Sitter (RN-AdS) black hole. First, we solve Klein-Gordon equation analytically by matching method. show that general quasinormal frequencies depend on relation between angular momentum quantum number, $\ensuremath{\ell}$, and $D$. When $\ensuremath{\ell}$ is (non-negative) integer multiple of $D\ensuremath{-}3$, i.e. $\ensuremath{\ell}=p(D\ensuremath{-}3)$, find an...
We study the first law of thermodynamics in IR modified H\v{o}rava-Lifshitz spacetime. Based on Bekenstein-Hawking entropy, we obtain integral formula and differential for Kehagias-Sfetsos black hole by treating $\omega$ as a new state parameter redefining mass that is just equal to $M_{ADM}$ obtained Myung\cite{YSM2} if take $\alpha=3\pi/8$.
We study the wave equation of a massive vector boson in background D-dimensional Schwarzschild black hole. The mass term introduces coupling between two physical degrees freedom field, and we solve resulting system ODEs numerically, without decoupling. show how to define decoupled transmission factors from an S-matrix compute them for various modes, masses space-time dimensions. lifts degeneracy transverse D=4, excites longitudinal particular s-wave. Moreover, it increases contribution waves...
Perturbations of asymptotically anti-de-Sitter (AdS) spacetimes are often considered by imposing field vanishing boundary conditions (BCs) at the AdS boundary. Such BCs, Dirichlet-type, imply a energy flux boundary, but converse is, generically, not true. Regarding as gravitational box, we consider (VEF) BCs more fundamental physical requirement and show that these can lead to new branch modes. As concrete example, Maxwell perturbations on Kerr-AdS black holes in Teukolsky formalism, our...
Based on the Sturm-Liouville eigenvalue problem, we develop a general analytic technique to investigate excited states of holographic superconductors. By including more higher order terms in expansion trial function, observe that results agree well with numeric data, which indicates method is very powerful study superconductors even if consider states. For both s-wave and p-wave models, find state has lower critical temperature than corresponding ground difference dimensionless chemical...
This thesis presents recent studies on test scalar and vector fields around black holes. It is separated in two parts according to the asymptotic properties of spacetime under study. In first part, we investigate Proca an asymptotically flat background. For field, obtain a complete set equations motion higher dimensional spherically symmetric backgrounds. These are solved numerically, both compute Hawking radiation spectra quasi-bound states. former case, carry out precise study longitudinal...
Some authors have recently found that the tunneling approach gives a different Hawking temperature for Schwarzschild black hole in coordinate system. In this paper, we find to work out system by approach, must use correct definition of energy radiating particles. By using new particle energy, obtain two dynamic systems, Kruskal-Szekers and Lemaitre systems.
We study Dirac quasinormal modes of Schwarzschild--anti--de Sitter (Schwarzschild-AdS) black holes, following the generic principle for allowed boundary conditions proposed in [M. Wang, C. Herdeiro, and M. O. P. Sampaio, Phys. Rev. D 92, 124006 (2015).]. After deriving equations motion fields on aforementioned background, we impose vanishing energy flux to solve these equations. find a set two Robin are allowed. These used calculate normal empty AdS Schwarzschild-AdS holes. In former case,...
We generalize our first analysis of the wave equation for a massive vector boson in background $D$-dimensional Schwarzschild black hole [C. Herdeiro, M. O. P. Sampaio, and Wang, Phys. Rev. D 85, 024005 (2012)], by adding charge to both field hole, on ($3+1$)-dimensional Standard Model brane. A detailed numerical study is performed obtain transmission factor coupled (as well as decoupled) system equations describing Proca modes, varying angular momentum number, mass, charge, space-time...
Abstract We establish the existence of stationary clouds massive test scalar fields around Kerr-MOG black holes. By solving Klein–Gordon equation numerically, we present lines in parameter space holes, and investigate effect MOG on rich structure clouds. observe that leads to split for clouds, larger makes it possible exist case lower background angular velocity. Numerical results are compared with analytical formula obtained by an asymptotic matching method, find both consistent each other....
We investigate the holographic p-wave superfluid in background metric of AdS soliton with $RF^{2}$ corrections. Two models, namely, Maxwell complex vector field model and Yang-Mills theory, are studied above context by employing Sturm-Liouville approach as well shooting method. When turning on spatial components gauge field, one observes that, probe limit, inclusion corrections hinders phase transition. On other hand, however, absence velocity, it is found that $RF^2$ lead to distinct...
We study the Maxwell quasinormal spectrum on asymptotically anti--de Sitter black holes with a set of two Robin type boundary conditions, by requiring energy flux to vanish at asymptotic infinity. Focusing, for illustrative purposes, Schwarzschild--anti--de both without and global monopole, we unveil that, one hand, bifurcates as hole radius increases which is termed mode split effect; while other an appropriate fixed but increasing monopole parameter, first (second) condition may trigger...
Abstract We generalize our previous studies on the Maxwell quasinormal modes around Schwarzschild-anti-de-Sitter black holes with Robin type vanishing energy flux boundary conditions, by adding a global monopole background. first formulate equations both in Regge–Wheeler–Zerilli and Teukolsky formalisms derive, based principle, two conditions each formalism. The are then solved analytically pure anti-de Sitter spacetimes monopole, different normal obtained due to existence of parameter. In...