View of thermodynamic phase transition of the charged Gauss-Bonnet AdS black hole via the shadow

We examine thermodynamic phase transition(PT)of the charged Gauss-Bonnet Ad S black hole(BH)by utilizing the shadow radius.In this system,we rescale the corresponding Gauss-Bonnet coefficientαby a factor of 1/(D-4),and ensure thatαis positive to avoid any singularity problems.The equation derived for the shadow radius indicates that it increases as the event horizon radius increases,making it an independent variable for determining BH temperature.By investigating the PT curve in relation to shadows,we can observe that the shadow radius can be used as an alternative to the event horizon radius in explaining the phenomenon of BH PT.Furthermore,the results indicate that an increase in the parameterαcorresponds to a decrease in the temperature of the BH.By utilizing the relationship between the temperature and the shadow radius,it is possible to obtain the thermal profile of the Gauss-Bonnet AdS BH.It is evident that there is an N-type variation in temperature for pressures P<P_(c).Additionally,as the parameterαincreases,the region covered by shadow expands while the temperature decreases.The utilization of BH shadows as a probe holds immense significance in gaining a deeper understanding of BH thermodynamic behavior.

Hawking radiation from Kerr-Newman de Sitter black hole via anomalies

In this paper, Hawking radiation from the Kerr Newman de Sitter black hole is studied via gauge anomaly and gravitational anomaly. The obtained results of Hawking radiation from the event horizon and the cosmological horizon accord with those by other methods.

Hawking radiation from the charged and magnetized BTZ black hole via covariant anomaly

This paper discusses Hawking radiation from the charged and magnetized Bafiados-Teitelboim-Zanelli （BTZ） black hole from the viewpoint of anomaly, initiated by Robinson and Wilczek recently. It reconstructs the electromagnetic field tensor and the Lagrangian of the field corresponding to the source with electric and magnetic charges to redefine an equivalent charge and gauge potential. It employs the covariant anomaly cancellation method to determine the compensating fluxes of charge flow and energy-momentum tensor, which are shown to match with those of the 2- dimensional blackbody radiation at the Hawking temperature exactly.

Hawking radiation from Kerr-Newman-Kasuya black hole via quantum anomalies

We have studied the Hawking radiation of the Kerr-Newman-Kasuya black hole via gauge and gravitational anomaly in the dragging coordinates. The fluxes of the electromagnetic current and the energy momentum tensor for each partial wave in two-dimensional field are obtained.

Hawking radiation from the dilaton-(anti) de Sitter black hole via covariant anomaly

Adopting the anomaly cancellation method, initiated by Robinson and Wilczek recently, this paper discusses Hawking radiation from the dilaton-（anti） de Sitter black hole. To save the underlying gauge and general covariance, it introduces covariant fluxes of gauge and energy-momentum tensor to cancel the gauge and gravitational anomalies. The result shows that the introduced compensating fluxes are equivalent to those of a 2-dimensional blackbody radiation at Hawking temperature with appropriate chemical potential.

Thermal analysis of the Rindler-Schwarzschild black hole via corrected entropy

In this study,we investigate the thermodynamic characteristics of the Rindler–Schwarzschild black hole solution.Our analysis encompasses the examination of energy emission,Gibbs free energy,and thermal fluctuations.We calculate various quantities such as the Hawking temperature,geometric mass,and heat capacity to assess the local and global thermodynamic stability.The temperature of the black hole is determined using the first law of thermodynamics,while the energy emission rate is evaluated as well.By computing the Gibbs free energy,we explore the phase transition behavior exhibited by Rindler–Schwarzschild black hole,specifically examining the swallowing tails.Moreover,we derive the corrected entropy to investigate the influence of thermal fluctuations on small and large black holes.Notably,we compare the impact of correction terms on the thermodynamic system by comparing the results obtained for large black holes and small black holes.

Hawking radiation from the Schwarzschild black hole with a global monopole via gravitational anomaly

This paper derives the Hawking flux from the Schwarzschild black hole with a global monopole by using Robinson and Wilczek＇s method. Adopting a dimensional reduction technique, it can describe the effective quantum field in the （3 ＋ 1）-dimensional global monopole background by an infinite collection of the （1 ＋ 1）-dimensional massless fields if neglecting the ingoing modes near the horizon, where the gravitational anomaly can be cancelled by the （1 ＋ 1）- dimensional black body radiation at the Hawking temperature.

Entropy correction of charged black hole via fermions tunneling beyond semi-classical approximation

Motivated by the idea of tunneling beyond semi-classical approximation of Majhi et al., we discuss entropy correction of Dirac particles tunneling from the Reissner-Nordstrm black hole with a global monopole. To get the corrections correctly, we regard the proportionality constants of quantum correction terms to the semi-classical term of action as the inverse of the square of the Planck Length but not that of the Planck Mass. Our study shows that corrections to the Bekenstein-Hawking entropy, namely the logarithmic term and the inverse area term, may be reproduced as the quantum effect is considered.

The Hawking radiation of the charged particle via tunnelling from the axisymmetric Sen black hole

Extending Parikh＇s semi-classical quantum tunnelling model, this paper has studied the Hawking radiation of the charged particle via tunnelling from the horizon of the axisymmetric Sen black hole. Different from the uncharged massless particle, the geodesics of the charged massive particle tunnelling from the horizon is not light-like. The derived result supports Parikh＇s opinion and provides a correct modification to Hawking strictly thermal spectrum developed by the fixed background space-time and not considering the energy conservation and the self-gravitation interaction.

Kerr Black Hole Geometry Leading to Dark Matter and Dark Energy via E-Infinity Theory and the Possibility of a Nano Spacetime Singularities Reactor

The present paper is basically a synthesis resulting from incorporating Kerr spinning black hole geometry into E-infinity topology, then letting the result bares on the vacuum zero point Casimir effect as well as the cosmic dark energy and dark matter density. In E-infinity theory a quantum particle is represented by a Hausdorff dimension Φ where Φ =2/(√5+1) . The quantum wave on the other hand is represented by Φ2 . To be wave and a particle simultaneously intersection theory leads us to?(Φ) (Φ)2= Φ3 which will be shown here to be twice the value of the famous Casimir force of the vacuum for a massless scalar field. Thus in the present work a basically topological interpretation of the Casimir effect is given as a natural intrinsic property of the geometrical topological structure of the quantum-Cantorian micro spacetime. This new interpretation compliments the earlier conventional interpretation as vacuum fluctuation or as a Schwinger source and links the Casimir energy to the so called missing dark energy density of the cosmos. From the view point of the present work Casimir pressure is a local effect acting on the Casimir plates constituting the local boundary condition while dark energy is nothing but the global combined effect of infinitely many quantum waves acting on the M&#246bius-like boundary of the holographic boundary of the entire universe. Since this higher dimensional M&#246bius-like boundary is one sided, there is no outside to balance the internal collective Casimir pressure which then manifests itself as the force behind cosmic expansion, that is to say, dark energy. Thus analogous to the exact irrational value of ordinary energy density of spacetime E(O)=(Φ5/2) mc2 we now have P (Casimir) = (Φ3/2)(ch/d2) where c is the speed of light, m is the mass, h is the Planck constant and d is the plate separation. In addition the new emerging geometry combined with the topology of E-infinity theory leads directly to identifying dark matter with the quasi matter of the ergosphere. As a direct consequence of this new insight E=mc2 which can be written as E = E (O) + E (D)?where the exact rational approximation is E (O)=mc2/22 is?the ordinary energy density of the cosmos and the exact rational approximation E (D)=mc2/(21/22) is the corresponding dark energy which could be subdivided once more albeit truly approximately into E(D)=mc2/(5/22)?+mc2/(16/22)??where 5 is the Kaluza Klein spacetime dimension, 16 are the bosonic extra dimensions of Heterotic superstrings and 5/22 □?22% is approximately the density of the dark matter-like energy of the ergosphere of the Kerr geometry. As for the actual design of our nano reactor, this is closely related to branching clusters of polymer, frequently called lattice animals. In other words we will have Casimir spheres instead of Casimir plates and these spheres will be basically nano particles modelling lattice animals. Here D=?4 will be regarded as spacetime dimensionality while D=6 of percolations are the compactified super string dimensions and D=8 is the dimension of a corresponding super space.

Hawking radiation via tunnelling from general stationary axisymmetric black holes

Hawking radiation is viewed as a tunnelling process. In this way the emission rates of massless particles and massive particles tunnelling across the event horizon of general stationary axisymmetric black holes are calculated, separately. The emission spectra of these two different kinds of outgoing particles have the same functional form and both are consistent with an underlying unitary theory.

Isogeometric Analysis and Shape Optimization of Holed Structures via the Patch Removing Technique

In this study,a patch removing based Isogeometric analysis(PR-IGA)method is proposed to conduct the holed structural analysis with only one parametric domain,in which there are also no trimmed elements.The theoretical foundation of this novel patch removing approach is that any holed structure can be obtained by removing sub-patches(i.e.,the holes)from an intact base patch.Since the parametric domains of these patches are all meshed by rectangular grids,the elements in the resulted holed structural parametric domain could all be untrimmed rectangles under certain mapping conditions.To achieve the special condition,a systematic technique consisting of T-spline local refinement and control points substitution/adjustment is provided.Due to the intactness of parametric elements,the analysis procedure of holed structures based on the proposed PRIGA is quite simplified and efficient compared to traditional multi-patch and trimming schemes.Moreover,after the deduction of analytical sensitivities related to structural mass and mechanical responses,the PR-IGA is directly employed in the holed structural shape optimization to successfully eliminate the need for model transformation during modeling,analysis and optimization processes.Numerical examples involving analysis and shape optimization of complex holed structures are presented to demonstrate the effectiveness of the proposed method.

Spectroscopy of the rotating BTZ black hole via adiabatic invariance

According to Bohr-Sommerfeld quantization rule,an equally spaced horizon area spectrum of a static,spherically symmetric black hole was obtained under an adiabatic invariant action.This method can be extended to the rotating black holes.As an example,this method is applied to the rotating BTZ black hole and the quantized spectrum of the horizon area is obtained.It is shown that the area spectrum of the rotating BTZ black hole is also equally spaced and irrelevant to the rotating parameter,which is consistent with the Bekenstein conjecture.Specifically,the derivation does not need the quasinormal frequencies and the small angular momentum limit.

Vibration Reduction by a Partitioned Dynamic Vibration Absorber with Acoustic Black Hole Features

Vibration quality is a vital indicator for assessing the progress of modern equipment.The dynamic vibration absorber(DVA)based on the acoustic black hole(ABH)feature is a new passive control method that manipulates waves.It offers efficient energy focalization and broad-spectrum vibration suppression,making it highly promising for applications in large equipment such as aircraft,trains,and ships.Despite previous advancements in ABH-DVA development,certain challenges remain,particularly in ensuring effective coupling with host structures during control.To address these issues,this study proposes a partitioned ABH-featured dynamic vibration absorber(PABH-DVA)with partitions in the radial direction of the disc.By employing a plate as the host structure,simulations and experiments were conducted,demonstrating that the PABH-DVA outperforms the original symmetric ABH-DVA in terms of damping performance.The study also calculated and compared the coupling coefficients of the two ABH-DVAs to uncover the mechanism behind the enhanced damping.Simulation results revealed that the PABH-DVA exhibits more coupled modes,occasionally with lower coupling coefficients than the symmetric ABH-DVA.The influence of frequency ratio and modal mass was further analyzed to explain the reasons behind the PABH-DVA's superior damping performance.Additionally,the study discussed the impact of the number of slits and their orientation.This research further explains the coupling mechanism between the ABH-DVA and the controlled structure,and provides new ideas for the further application of ABH in engineering.

Unruh-Verlinde temperature and energy of (2+1)-dimensional matter coupled black hole via entropic force

Verlinde＇s recent work, which shows that gravity may be explained as an entropic force caused by the changes in information associated with the positions of material bodies, is extended to study the Unruh-Verlinde temperature and energy of a static spherically symmetric charged black hole. The results indicate that the Unruh-Verlinde temperature is equal to the Hawking temperature at the event horizon. The energy is dependent on the radius of the screen, which is Mso a consequence of the Gauss＇ laws of gravity and electrostatics.

Extraction energy from charged Vaidya black hole via the Penrose process

In this paper,we consider the analogy of the Penrose process in charged Vaidya spacetime.We calculate the border of the generalized ergosphere,in which the charged particles with negative energy might exist,and show that it is temporary.We show that there are no closed orbits for particles with negative energy inside the generalized ergosphere.We investigate the question about the efficiency of the Penrose process and show that one cannot extract large energies from a black hole if the velocities of ingoing and outgoing particles are of the same order.In the case of the extremal black hole,we show that the upper limit is restricted by the absolute value of the electric charge per mass.

Measuring solar irradiance profiles in the Arctic sea ice using fiber optic spectrometry via inclined holes

An irradiance profile measurement approach and profiling system were developed to measure the solar irradiance profile of the Arctic sea ice using fiber optic spectrometry.The approach involved using a miniature spectrometer to sense light signals collected and transmitted from a fiber probe.The fiber probe was small,and could thus move freely in inclined bore holes drilled in sea ice with its optical entrance pointing upward.The input-output relationship of the system was analyzed and built.Influence factors that determined the system output were analyzed.A correctional system output approach was proposed to correct the influence of these factors,and to obtain the solar irradiance profile based on the measurements outputted by this system.The overall performance of the system was examined in two ice floes in the Arctic during the 9th Chinese National Arctic Research Expedition.The measured solar irradiance profiles were in good agreement with those obtained using other commercially available oceanographic radiometers.The derived apparent optical properties of sea ice were comparable to those of similar sea ice measured by other optical instruments.

Area and entropy spectra of black holes via an adiabatic invariant

By considering and using an adiabatic invariant for black holes, the area and entropy spectra of static spherically- symmetric black holes are investigated. Without using quasi-normal modes of black holes, equally-spaced area and entropy spectra are derived by only utilizing the adiabatic invariant. The spectra for non-charged and charged black holes are calculated, respectively. All these results are consistent with the original Bekenstein spectra.

Hawking Radiation of Charged Particles via Tunneling from a Cylindrically Symmetric Black Hole in Anti-de Sitter Space-Time

Applying Parikh-Wilzcek＇s semi-classical quantum tunneling model, we study the Hawking radiation of charged particles as tunneling from the event horizon of a cylindrically symmetric black hole in anti-de Sitter space-time. The derived result shows that the tunneling rate of charged particles is related to the change of Bekenstein-Hawking entropy and that the radiation spectrum is not strictly pure thermal after taking the black hole background dynamical and self-gravitation interaction into account, but is consistent with the underlying unitary theory.

Hawking Radiation from Horizons of Reissner-Nordstrm de Sitter Black Hole with a Global Monopole via Anomalies

Hawking radiation from cosmological horizon and event horizon of the Reissner-Nordstrom de Sitter black hole with a global monopole is studied via a new method that was propounded by Robinson and Wilzek and elaborated by Banerjee and Kulkarni. The results show that the gauge current and energy-momentum tensor fluxes, which required keeping gauge covariance and general coordinate invariance at the quantum level in the effective field theory, are exactly equivalent to those of Hawking radiation from the event horizon and the cosmological horizon, respectively.