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Jiliang Jing

Publications and source records attributed to Jiliang Jing.

At least 55 records · Page 3Linked to original sources

Extracting energy from plunging region of a Kerr-Taub-NUT black hole by magnetic reconnection

We have studied the energy extraction from a Kerr-Taub-NUT black hole via magnetic reconnection occurring in the plunging region. Our results show that the gravitomagnetic charge suppresses the energy extraction process through magnetic reconnection and reduces the corresponding extraction efficiency, which is opposite to the effects of the black hole spin and the magnetization parameter. Finally, we treat the energy extraction process through magnetic reconnection as a mechanism to revisit the problem of the observed jet power and radiative efficiency of GRS 1915+105. Our results show that the allowed black hole parameter region originating from the jet power has an intersection with the region from the radiative efficiency. This means that with this mechanism related to magnetic reconnection the Kerr-Taub-NUT metric can simultaneously explain the observed jet power and radiative efficiency for GRS 1915+105, which is not explained by other mechanisms in previous studies.

gr-qc↗

Near-horizon polarized images of a rotating hairy Horndeski black hole

Recently, Hou \emph{et al.} [Astrophys. J. Lett. \textbf{988}, L51 (2025)] revealed that the Electric Vector Position Angle (EVPA) of polarization vectors in the near-horizon images is governed solely by the spacetime geometry and is irrespective of the plasma flows. Here, we generalize the study to the scenario of a rotating hair black hole within the Horndeski gravity and probe the effects of the hairy parameter on the EVPA. For a fixed inclination, the hairy parameter enhances the observed EVPA in the slowly rotating case, but decreases it in the rapidly rotating case. For a fixed black hole spin, the influence of the hairy parameter on the observed EVPA under different observer inclinations is further modulated by the azimuthal angle of the observed polarization vector. The hairy parameter's impact is more distinct in the low inclination case as the azimuthal angle lies within a specific range, but is almost independent of the observer inclination as the azimuthal angle is beyond this specific range. Furthermore, the dependence of the hairy parameter's impact on the EVPA is stronger with respect to the black hole spin than to the inclination angle. These results could help to further understand the near-horizon polarized images and Horndeski gravity.

gr-qc↗

Probing Kalb-Ramond field with extreme mass ratio inspirals

The extreme-mass-ratio inspirals (EMRIs) are emerging as precision laboratories for testing the gravity beyond general relativity. In this work, we investigate the Lorentz symmetry breaking (LSB) effect induced by the Kalb-Ramond (KR) field on the gravitational waveforms from the EMRI system. We observe that the LSB parameter $l$ appears in the leading order for the corrections of energy and angular momentum fluxes, and as $|l|$ increases, the differences in EMRI waveforms between the KR black hole and Schwarzschild black hole become more pronounced. We note that the LSB effect becomes detectable by LISA for values of $|l|\sim 10^{-6}$ with a one-year observation period. Furthermore, we use the Fisher information matrix (FIM) approach for the parameter estimation and find the detection error for $l$ can be constrained to $Δl \sim 10^{-5}$ at $\mathrm{SNR} = 20$, demonstrating the potential of space-based gravitational wave detectors to rigorously test the KR field.

gr-qc↗

Effective one-body theory of spinless binary evolution dynamics

The effective one-body (EOB) theory provides an innovative framework for analyzing the dynamics of binary systems, as articulated by Hamilton's equations. This paper investigates a self-consistent EOB theory specifically tailored for the dynamics of such systems. Our methodology begins by emphasizing how to effectively utilize the metrics derived from scattering angles in the analysis of binary black hole mergers. We then construct an effective Hamiltonian and formulate a decoupled, variable-separated Teukolsky-like equation for $ψ^B_4$. Furthermore, we present the formal solution to this equation, detailing the energy flux, radiation-reaction force (RRF), and waveforms for the ``plus" and ``cross" modes generated by spinless binaries. Finally, we carry out numerical calculations using the EOB theory and compare the results with numerical relativity (NR) data from the SXS collaboration. The results indicate that to the innermost stable circular orbit, the binding energy -- angular momentum relation differs from the NR results by less than $5$\textperthousand, with a larger mass ratio yielding better agreement.

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Dissipation suppression for an Unruh-DeWitt battery with a reflecting boundary

In the framework of open quantum systems, we study the dynamics of an accelerated quantum battery (QB), modeled as an Unruh-DeWitt detector interacting with a real massless scalar quantum field. The QB is driven by an external classical force acting as a charger. A major challenge in this setup is the environment-induced decoherence, which leads to energy dissipation of the QB. Accelerated motion exacerbates this dissipation, manifesting effects analogous to those experienced by a static QB in a thermal bath in free space, consistent with the Unruh effect. To overcome these challenges, we introduce a reflecting boundary in a space, which modifies the vacuum fluctuations of the field and leads to a position-dependent suppression of dissipation for the Unruh-DeWitt QB. Our analysis reveals that as the QB approaches the boundary, the relevant dissipation is significantly reduced. In particular, when the QB is placed extremely close to the boundary, the dissipation is nearly eliminated, as if the QB were a closed system. Furthermore, we identify a characteristic length scale associated with the acceleration of QB. When the distance between the QB and the boundary is much smaller than this scale, the boundary effectively suppresses dissipation, and this suppression effect becomes identical for both an accelerated QB and a static QB in a thermal bath. Conversely, when the distance is beyond this scale, the suppression effect weakens and manifests a significant difference between these two cases. Our findings demonstrate the potential of boundary-induced modifications in vacuum fluctuations to effectively suppress dissipation, offering valuable insights for optimizing QB performance. This work paves the way for the development of high-efficiency quantum energy storage systems in the relativistic framework.

hep-th↗

Scalar-gravitational quasinormal modes and echoes in a five dimensional thick brane

The scalar perturbations of thick braneworld models provide critical insights into their matter-geometry relationship, distinct from tensor modes. This work systematically investigates quasinormal modes and gravitational echoes from scalar perturbations in a thick brane model exhibiting internal structure and brane splitting. Using the WKB method, direct integration, and Bernstein spectral techniques, we compute quasinormal frequencies across different parameter regimes, addressing both single and double-barrier effective potentials. Time-domain evolution of wave packets reveals clear echo signals for split brane configurations ($s > 1, δ> 1$), produced by successive reflections between sub-branes. A key finding is the position-dependence of echo modes within the extra dimension: observers located on a sub-brane detect clean periodic signals, whereas those situated between sub-branes observe more complex, modulated waveforms. This effect offers a distinct signature of the brane's internal structure. The observed echoes, along with consistent frequency- and time-domain results, advance the understanding of thick brane dynamics and open an observational window into warped extra dimensions. Moreover, the similarity between the effective potential in thick brane scenarios and those of black holes and wormholes offers valuable perspectives for studying echo-related phenomena in these gravitational systems.

gr-qc↗

Thin accretion disk around a Kerr black hole immersed in swirling universes

We have studied the properties of thin accretion disks around swirling-Kerr black holes, which own an extra swirling parameter describing the rotation of the immersed universe. Our results show that the swirling parameter leaves distinct imprints on the energy flux, temperature distribution and emission spectra of the disk and gives rise to some new effects that differ from those induced by the black hole's spin. With the increasing of the swirling parameter, both the energy flux and radiated temperature in the disk increase in the inner region where circular orbital radii are smaller and decrease in the outer region where circular orbital radii are larger. In contrast, these quantities consistently increase with the black hole's spin. Although the swirling parameter and the black hole's spin parameter lead to higher cut-off frequencies, the background swirling reduces the observed luminosity of the disk at lower frequencies and enhances it only at higher frequencies, which is quite distinct from that of the black hole's spin. Furthermore, the conversion efficiency increases with the black hole's spin parameter, but decreases with the swirling parameters. Additionally, the effects of the swirling parameter are found to be suppressed by the black hole's spin parameter. These results could help us further understand the properties of thin accretion disks and the swirling of the universe background.

gr-qc↗

Dictionary revision for mapping boundary data to bound states

The correspondence between gravitational observables derived from scattering processes and adiabatic invariants in bound orbits, within the framework of the Post-Minkowskian (PM) expansion, has garnered significant attention in the study of bound orbital systems. However, the existing dictionary for this correspondence, \textcolor{black}{characterized by the transformation $β\rightarrow i β$ and $b\rightarrow \pm i |b|$ with $β=arccosh γ$}, produces complex-valued quantities of bound orbits in 4PM calculations. These results contradict fundamental physical principles, thereby highlighting deficiencies in the existing dictionary. Our research identifies a critical issue: the Fourier transform of the scattering amplitude incorporates a factor of $(p_\infty^2)^{-n/2}$. This factor introduces singularities at $p_\infty^2 = 0$, thereby rendering the original dictionary become ineffective, as it assumes the possibility of connecting both scattering states and bound states at the singular point. We propose a rigorous modification by employing Hawking's method for black hole radiation, specifically analytical continuing $p_\infty^2 \rightarrow p_\infty^2 e^{-i π}$. We also evaluate the new dictionary by comparing the binding energy calculated using effective one-body theory with numerical relativity simulation data from the SXS collaboration. Our findings indicate a remarkable agreement between the two sets of results. This revised dictionary enhances the applicability of gravitational observables derived from scattering processes to bound orbits and effectively fulfills the objectives envisioned by the pioneers who proposed this correspondence.

gr-qc↗

Quantum Signatures of Chaos in Anisotropic Quantum Rabi Model

Quantum chaos is an intriguing topic and has attracted a great deal of interests in quantum mechanics and black hole physics. Recently, the exponential growth of out-of-time-ordered correlator (OTOC) has been proposed to diagnose quantum chaos and verify the correspondence principle. Here, good correspondence is found between the linear entanglement entropy and the semiclassical phase space structures in the anisotropic quantum Rabi model. The Loschmidt echo in the chaotic sea decays more faster than that in the stable island. However, the OTOCs grow exponentially at early times for the initial states centered both in the chaotic and stable regions. The exponential growth of the OTOC is attributed to quantum collapse that provides a novel mechanism of yielding exponential growth of the OTOC in quantum systems. Moreover, the quantum collapse effect is more obvious for the initial states centered in the chaotic one. The results show that in the anisotropic quantum Rabi model, the linear entanglement entropy, and Loschmidt echo are more effective than OTOC for diagnosing quantum chaotic signals.

quant-ph↗

Long-time signatures of chaos in large atom-light frequency ratios Rabi model

As one of the famous effects in quantum Rabi model (QRM), Rabi oscillation may lead to the occurrence of quantum dynamics behaviors without classical dynamic counterparts, such as quantum collapse and revival effects. In this paper, we focus on studying the long-time quantum signatures of chaos in the large atom-light frequency ratios Rabi model. It is shown that the saturated values of the entanglement entropy for initial states located in chaotic sea are higher than that in the regular regions, and the Husimi Q function are more dispersed in phase space. Moreover, we observed that the long-time average entanglement entropy and spin variance correspond well with the semiclassical phase space. Our results imply that the correspondence principle does not invalidated by quantum collapse and revival effects in the large atom-light frequency ratios Rabi model.

quant-ph↗

Using nanokelvin quantum thermometry to detect timelike Unruh effect in a Bose-Einstein condensate

It is found that the Unruh effect can not only arise out of the entanglement between two sets of modes spanning the left and right Rindler wedges, but also between modes spanning the future and past light cones. Furthermore, an inertial Unruh-DeWitt detector along a spacetime trajectory in one of these cones may exhibit the same thermal response to the vacuum as that of an accelerated detector confined in the Rindler wedge. This feature thus could be an alternative candidate to verify the ``Unruh effect", termed as the timelike Unruh effect correspondingly. In this paper we propose to detect the timelike Unruh effect by using an impurity immersed in a Bose-Einstein condensate (BEC). The impurity acts as the detector which interacts with the density fluctuations in the condensate, working as an effective quantum field. Following the paradigm of the emerging field of quantum thermometry, we combine quantum parameter estimation theory with the theory of open quantum systems to realize a nondemolition Unruh temperature measurement in the nanokelvin (nK) regime. Our results demonstrate that the timelike Unruh effect can be probed using a stationary two-level impurity with time-dependent energy gap immersed in a BEC within current technologies.

hep-th↗

Dissipative dynamics of an open quantum battery in the BTZ spacetime

We consider how charging performances of a quantum battery, modeled as a two-level system, are influenced by the presence of vacuum fluctuations of a quantum field satisfying the Dirichlet, transparent, and Neumann boundary conditions in the BTZ spacetime. The quantum battery is subjected to an external static driving which works as a charger. Meanwhile, the quantum field is assumed to be coupled to both longitudinal and transverse spin components of the quantum battery including decoherence and pure dephasing mechanisms. Charging and discharging dynamics of the quantum battery are derived by extending the previous open quantum system approach in the relativistic framework to this more general scenario including both the driving and multiple coupling. Analytic expressions for the time evolution of the energy stored are presented. We find that when the driving amplitude is stronger/weaker than the energy-level spacing of the quantum battery the pure dephasing dissipative coupling results in better/worse charging performances than the decoherence dissipative coupling case. We also find that higher Hawking temperature helps to improve the charging performance under certain conditions compared with the closed quantum buttery case, implying the feasibility of energy extraction from vacuum fluctuations in curved spacetime via dissipation in charging protocol. Different boundary conditions for quantum field may lead to different charging performance. Furthermore, we also address the charging stability by monitoring the energy behaviour after the charging protocol has been switched off. Our study presents a general framework to investigate relaxation effects in curved spacetime, and reveals how spacetime properties and field boundary condition affect the charging process, which in turn may shed light on the exploration of the spacetime properties and thermodynamics via the charging protocol.

hep-th↗

Stationary scalar clouds around a rotating BTZ-like black hole in the Einstein-bumblebee gravity

We have studied stationary clouds of massive scalar fields around a rotating BTZ-like black hole in the Einstein-bumblebee gravity, by imposing the Robin type boundary conditions at the AdS boundary. We establish, by scanning the parameter space, the existence of \textit{fundamental} stationary scalar clouds ($i.e.$, the overtone number $n=0$). In particular, we observe that the Lorentz symmetry breaking parameter $s$ and the quantum number $k$ play an opposite role in determining scalar clouds, which indicates the existence of \textit{degenerate} scalar clouds. To illustrate the fact that scalar clouds may only be supported for the $n=0$ case, we have analyzed the impact of various parameters on scalar quasinormal modes. It is shown that the Lorentz symmetry breaking parameter $s$ does not change the superradiance condition, and superradiant instabilities only appear for the fundamental modes. Our work shows that the Lorentz symmetry breaking provides richer physics in stationary scalar clouds around black holes.

gr-qc↗

Magnetic reconnection and energy extraction from a Konoplya Zhidenko rotating non Kerr black hole

Recently, magnetic reconnection has attracted considerable attention as a novel energy extraction mechanism, relying on the rapid reconnection of magnetic field lines within the ergosphere. We have investigated the properties of the energy extraction via magnetic reconnection in a Konoplya-Zhidenko rotating non-Kerr black hole spacetime with an extra deformation parameter. Our results show that the positive deformation parameter expands the possible region of energy extraction and improves the maximum power, maximum efficiency, and the maximum ratio of energy extraction between magnetic reconnection and the Blandford-Znajek process. This means that in the Konoplya-Zhidenko rotating non-Kerr black hole spacetime one can extract more energy via magnetic reconnection than in the Kerr black hole case. These effects of the deformation parameter may provide valuable clues for future astronomical observations of black holes and verification of gravity theories.

gr-qc↗

Quantum instability and Ehrenfest time for an inverted harmonic oscillator

We investigate the classical-quantum correspondence in the inverted harmonic oscillator (IHO) system. It is shown that the out-of-time-order correlators (OTOCs) which the initial states are located at any position in the IHO system possess the same exponential growth rates (EGRs) as that at the saddle point, and their EGRs are twice the classical lyapunov exponent (CLE) of the saddle point. Through the time evolution of mean photon number and the OTOCs, we exhibit that the classical-quantum correspondence in the IHO system not only depends on the initial system photon number, but also on the central positions of the initial states in the phase space. Moreover, we use the Husimi Q function to visualize the quantum wave packets during the OTOCs grow exponentially.

quant-ph↗

Signatures from the observed jet power and the radiative efficiency for rotating black holes in loop quantum gravity

We investigate the radiative efficiency and jet power in the spacetime of a rotating black hole within the framework of loop quantum gravity (LQG), which includes an additional LQG parameter. The results show that as the LQG parameter increases, the radiative efficiency decreases for slowly rotating black holes while it increases for rapidly rotating black holes. Furthermore, the jet power is found to increase for different black hole spins. With the observed data from the well-known sources A0620-00, H1743-322, XTE J1550-564, GRS1124-683, GRO J1655-40, and GRS1915+105, we make some constraints on the black hole spin parameter and the LQG parameter. The presence of the LQG parameter broadens the allowed range of the black hole spin parameter for sources A0620-00, H1743-322, XTE J1550-564 and GRO J1655-40. However, for the source GRS 1915+105, there is no overlap between the allowed parameter regions, which implies that the rotating LQG black hole cannot simultaneously account for the observed jet power and the radiative efficiency as in other black hole spacetimes.

gr-qc↗

Precessions of spherical orbits in the rotating Melvin black hole spacetime and its constraints from the jet of M87*

We investigate precessions of spherical orbits of timelike particles in the background of a rotating black hole immersed in the Melvin magnetic field, and probe effects of the magnetic field on the precession period. Our results show that effects of the magnetic field on the particles' motions gradually decrease with the titled angle and finally vanish as the titled angle tends to $π/2$. With the increase of the magnetic field parameter, we find that the precession becomes rapidly. Modelling the spherical orbit to the warp radius in the accretion disk and with the observed precession period from the jet of M87*, we analyze the allowed regions of the black hole parameters and the warp radius in the accretion disk. Especially, we find a novel degenerated phenomenon of precession periods arising from magnetic field for two different spherical orbits, which does not appear in the usual Kerr black hole case. Moreover, we also discuss the possibility of observing effects of the magnetic field on the precession periods of jets for astrophysical black holes. Our study could help to further understand the rotating Melvin black hole and the relationship between magnetic fields and precessions of jets.

gr-qc↗

Chaotic motion of particles in the spacetime of a Kerr black hole immersed in swirling universes

We investigate the motion of particles in the spacetime of a Kerr black hole immersed in swirling universes. Using the Poincaré section, fast Lyapunov exponent indicator, bifurcation diagram and basins of attraction, we present the effects of the swirling parameter and the spin parameter on the dynamical behaviors of the motion of particles, and confirm the presence of chaos in the motion of particles in this background spacetime. We find that the swirling parameter can change the range of the spin parameter where the chaos occurs, and vice versa. Moreover, we observe clearly that, regardless of the spin parameter, there exist some self-similar fractal fine structures in the basins boundaries of attractors for the spacetime of a black hole immersed in swirling universes. The combination the swirling parameter and the spin parameter provides richer physics in the motion of particles.

gr-qc↗