arXiv subjects

Jian-Pin Wu

Publications and source records attributed to Jian-Pin Wu.

At least 19 recordsLinked to original sources

arXiv2026

Probing Dark Matter with Gravitational Waves: Spin-Modulated Dephasing from Black Holes in Halos

We develop a novel analytical framework for constructing axisymmetric black hole spacetimes sourced by dark matter (DM) halos. Applying this to extreme mass ratio inspirals (EMRIs), we find that the DM induces a detectable gravitational-wave dephasing, scaling monotonically with the halo's compactness. Notably, BH spin significantly suppresses this dephasing, indicating that analyses neglecting rotation would overestimate DM signatures. Faithfulness calculations confirm that future space-borne detectors can robustly distinguish such DM environments, establishing EMRIs as a novel probe for galactic DM distributions.

gr-qc↗

arXiv2026

A Minkowski-core black hole with cosmological constant and electric charge

Within a covariant effective Hamiltonian framework, we employ an inverse construction to derive the gravitational Hamiltonian constraint for a Minkowski-core regular black hole without invoking exotic matter. We then extend the constraint by coupling it to a spherically reduced Maxwell field and including a cosmological constant. The resulting charged anti-de Sitter (AdS) and de Sitter (dS) solution is gauge independent and reduces to the Reissner--Nordstr\"om--AdS (RN-AdS) black hole when the regularization parameter vanishes. Electric charge and a cosmological constant preserve the Minkowski core: the metric approaches the Minkowski geometry at the center, the Kretschmann scalar vanishes there, and the spacetime exhibits a multi-horizon structure. Focusing on AdS backgrounds, we investigate the black hole thermodynamics. For a regularization parameter below a critical value, the model exhibits a phase transition with consistent signatures across these thermodynamic quantities, demonstrating that Minkowski-core regularization can preserve center regularity while modifying the AdS thermodynamic phase structure relative to the RN-AdS benchmark.

gr-qc↗

arXiv2026

Properties of holographic superconductors from Machine Learning

We investigate holographic superconductors using modern optimisation techniques inspired by machine learning. The critical temperature is obtained by minimising the variational functional for the eigenvalue $\lambda^2$ with two complementary trial functions: a simple cosine ansatz $F(z)=\cos(a z)$ and a flexible exponential polynomial $F(z)=\exp(\sum_{n=2}^{N} a_n z^n)$, both of which automatically satisfy the standard boundary conditions. For the cosine ansatz, we perform a one-parameter minimisation and obtain $\lambda^2(\Delta)$ and $T_c/\sqrt{\rho}$ over a wide range of $\Delta$, including the exact values at $\Delta=1$ and $\Delta=2$ to high accuracy. The exponential polynomial ansatz, with up to 19 coefficients, is optimised using a multi-start L-BFGS-B algorithm with warm-starting, yielding even better agreement with known exact results. Our numerical data for $\lambda^2(\Delta)$ and $T_c/\sqrt{\rho}$ match the analytical predictions from the literature, confirming the robustness of the variational approach. This work; therefore, demonstrates that a combination of analytic trial functions and modern numerical optimisation provides a powerful, flexible, and efficient tool for exploring holographic superconductors, and can be readily extended to include backreaction or other sectors in this field.

hep-th↗

arXiv2026

Echoes and quasinormal modes for static loop quantum black bounces

We investigate scalar perturbations of the static loop quantum black bounce (LQBB) spacetime with multipole index $l=1$, focusing on time-domain signals and fundamental quasinormal frequencies (QNFs). The LQBB model provides a unified description of regular black holes (RBHs) and traversable wormholes, governed by the quantum parameter $\alpha$ and the bounce parameter $r_b$. Using the finite difference method, we find no echoes for the displayed RBH configurations with a single-barrier effective potential, whereas clear echoes are produced by the potential well structure in selected traversable wormhole configurations. The QNFs obtained from the Prony method and the direct integration method are in good agreement. In the RBH case, increasing $r_b$ or $\alpha$ leads to a slower decay. In the wormhole case, the QNFs depend non-monotonically on the model parameters, and the emergence of echoes is closely tied to the effective potential profile. These results show that the LQBB spacetime provides a useful framework for studying wave dynamics in RBHs and traversable wormholes, and for clarifying how horizon and throat structures affect ringdown and echoes.

gr-qc↗

arXiv2026

Quasinormal modes of a rotating loop quantum black hole

We investigate the quasinormal modes of a massless scalar field on an effective rotating loop quantum black hole background, constructed from a covariant spherical model via an improved Newman-Janis algorithm. Using the continued fraction method, we compute the spectrum for both fundamental and overtone modes, and systematically analyze how the frequencies depend on the quantum correction, spin, and angular structure of the perturbation. For all fundamental modes, increasing the quantum gravity correction monotonically reduces both the oscillation frequency and the damping rate, signaling slower oscillations and prolonged decay. Rotation imprints a nontrivial modulation: for a spherically symmetric perturbation, the real frequency displays a crossover as the spin grows, whereas this feature is suppressed once angular momentum is turned on; further activating the azimuthal component enhances the frequency and reduces the damping even more strongly. In the overtone sector, the rotating solution retains the hallmark quantum gravitational signatures of the spherical case - overtone outbursts and non-monotonic evolution - with rotation shifting these phenomena to weaker quantum corrections. Nonzero orbital angular momentum suppresses the outbursts, while the azimuthal degree of freedom boosts the frequency, giving rise to novel spectral inversions among higher overtones. Our results confirm that the effective rotating metric captures essential loop quantum gravity features, providing clear theoretical benchmarks for black hole spectroscopy and future gravitational-wave observations.

gr-qc↗

arXiv2026

Assessing EMRI Detectability of the Rotating Quantum Oppenheimer-Snyder Black Hole

This letter presents an assessment of quantum gravity effects on extreme-mass-ratio inspirals (EMRIs) for the rotating quantum Oppenheimer-Snyder (qOS) black hole. Employing the adiabatic evolution, we compute the gravitational wave (GW) dephasing, which quantifies the cumulative phase shift induced by the quantum correction {\alpha} . We further generate the augmented analytic kludge (AAK) waveform and investigate the faithfulness between the waveforms with and without the quantum parameter {\alpha} for different values of a. Our results reveal that the quantum gravity effect induces detectable imprints in LISA, while the presence of rotation suppresses these signatures. This suggests that rotational degrees of freedom must be carefully accounted for when probing quantum gravity with EMRI observations.

gr-qc↗

arXiv2026

Quantum criticality and mixed-state entanglement in holographic superconductor--insulator transitions

We study quantum criticality in a holographic Einstein--Maxwell--Dilaton--Axion (EMDA) p-wave superconductor exhibiting a superconductor--insulator transition (SIT). By tracking the superconducting energy gap, we show that approaching the quantum critical point (QCP) closes the gap and induces incipient insulating features, indicating that enhanced quantum fluctuations suppress superconducting order and trigger the SIT. We suggest that this behavior occurs only when the condensate orientation is aligned with the direction of translational symmetry breaking. To probe the transition, we employ two holographic indicators: holographic entanglement entropy (HEE) and the entanglement wedge cross-section (EWCS), the latter being a mixed-state entanglement measure. In contrast to HEE, which for sufficiently large configuration is dominated by the thermal entropy and is therefore largely insensitive to entanglement along the temperature direction, EWCS displays pronounced critical scaling and provides a robust diagnostic of the quantum phase transition (QPT). We attribute this contrast to the fact that HEE at large scales is controlled by the infrared (IR) geometry, whereas EWCS is governed by deformations of the entire bulk. Our results establish EWCS as a robust probe of holographic quantum criticality in mixed states.

hep-th↗

arXiv2026

Probing Quantum Gravity effects with Extreme Mass Ratio Inspirals around Rotating Hayward Black Holes

We investigate extreme mass-ratio inspirals (EMRIs) around a rotating Hayward black hole to assess the detectability of signatures arising from quantum gravity.The quantum parameter $\alpha_0$, which encodes deviations from general relativity (GR), introduces extra correction terms in both the orbital frequency and the fluxes. Our results show that after one year of accumulated observation, these corrections induce a detectable dephasing in the EMRI waveform. Using the modified orbital evolution driven by $\alpha_0$, we generate waveforms via the augmented analytic kludge (AAK) model implemented in the \texttt{FastEMRIWaveforms} package. Furthermore, we utilize the time-delay interferometry (TDI) to suppress the laser noise and phase fluctuations induced by spacecraft motion, and then employ the Fisher information matrix (FIM) to test the sensitivity of LISA in detecting deviations from GR. Our results demonstrate the potential of LISA to probe quantum-gravity effects through high-precision observations of EMRIs.

gr-qc↗

arXiv2026

Chaos as a Possible Probe for Scalar Hair in Horndeski Gravity

The detection of black hole scalar hair, a possible deviation from general relativity's "no-hair" theorem, requires sensitive probes beyond conventional methods. This study proposes chaotic dynamics as a novel indicator for scalar hair in Horndeski gravity. We investigate the motion of a spinning test particle in a static, spherically symmetric hairy black hole spacetime. Our results show that increasing scalar hair systematically suppresses orbital chaos, as evidenced by regularized precession, reduced Lyapunov exponents, and contracted Poincare sections. Furthermore, scalar hair enhances the correlation between the two gravitational wave polarization modes, restoring phase coherence. These findings demonstrate that chaotic observables and gravitational wave signatures can jointly serve as sensitive probes for black hole hair, offering a complementary approach to testing gravity in strong-field regimes.

gr-qc↗

arXiv2026

Imprints of quantum gravity effects on gravitational waves: a comparative study using extreme mass-ratio inspirals

Within a generally covariant Hamiltonian framework of loop quantum gravity (LQG), two black hole models parameterized by a quantum correction $\zeta$ have recently been constructed. Using extreme mass-ratio inspirals (EMRIs) as high-precision probes, we investigate the imprints of this LQG deformation in the surrounding spacetime. Waveforms generated via an improved augmented analytic kludge (AAK) model in both LQG black hole backgrounds and in Schwarzschild spacetime are compared through a faithfulness analysis. This allows us to quantify the detectability of the deviation with LISA and to derive constraints on $\zeta$ based on a detection threshold. We find that the first LQG black hole model produces significantly stronger signatures in EMRI signals than the second, making its quantum gravity effects more accessible to future space-borne gravitational-wave detection.

gr-qc↗

arXiv2025

Diagnosing Critical Behavior in AdS Einstein-Maxwell-Scalar Theory via Holographic Entanglement Measures

We investigate the holographic mixed-state entanglement measures in the Einstein-Maxwell-Scalar (EMS) theory. Several quantities are computed, including the holographic entanglement entropy (HEE), mutual information (MI), entanglement wedge cross-section (EWCS), and butterfly velocity ($v_B$). Our findings demonstrate that these measures can effectively diagnose phase transitions. Notably, EWCS and MI, as mixed-state entanglement measures, exhibit behavior opposite to that of the HEE. Additionally, we study the butterfly velocity, a dynamic quantum information measure, and observe that it behaves differently from the static quantum information measures. We analyze the butterfly velocity and find that its non-monotonic behavior arises from the competition between two contributions in its expression, which the analytic structure suggests may be correlated with distinct physical interpretations. Moreover, we examine the scaling behavior of the holographic entanglement measures and find that all the critical exponents are equal to $1$, which is twice that of the scalar field. We also explore the inequality between EWCS and MI, noting that the growth rate of MI consistently exceeds that of EWCS during phase transitions. These features are expected to be universal across thermodynamic phase transitions, with the inequalities becoming more significant as one moves away from the critical point.

hep-th↗

arXiv2025

Mixed-state entanglement and phase transitions in Einstein-Born-Infeld massive gravity

We study mixed-state entanglement measures in Einstein-Born-Infeld (EBI) massive gravity theory, a model exhibiting both Hawking-Page phase transitions and effective metal-insulator transitions (MIT) at finite temperatures. Our comprehensive investigation reveals that the entanglement wedge cross-section (EWCS), a holographic probe of mixed-state entanglement structure, demonstrates distinctive properties in detecting phase transitions. For the effective MIT, we find that the higher-order terms of EWCS align closely with the crossover temperature, a feature not shared by holographic entanglement entropy (HEE). This sensitivity makes EWCS a complementary geometric tool for probing effective phase transitions at finite temperatures. In Hawking-Page phase transitions, we observe that all entanglement measures effectively diagnose both first-order and second-order phase transitions, with EWCS showing configuration-independent behavior. Importantly, we discover that all geometry-related quantities, including entanglement measures, demonstrate a universal critical exponent of 1/3 near the second-order phase transition point. This result suggests a fundamental connection between quantum information theory and critical phenomena in gravitational systems, and also highlights the potential of EWCS as a powerful probe for phase transitions.

hep-th↗

arXiv2025

Non-singular cosmologies matching regular black holes

We construct a new non-singular cosmological model matched to a Minkowski-core regular black hole by means of a modified Oppenheimer--Snyder framework. Its dynamics is studied in both dust-only and scalar-field scenarios, and compared with that of two other non-singular models as well as the classical standard cosmology. The results show that, although all three non-singular cosmologies share identical late-time behavior and allow for a natural embedding of inflation in the scalar-field setting, they exhibit qualitatively distinct non-singular features at very early times. In particular, the new cosmology approaches Minkowski spacetime in the limits of both the infinite past and the infinite future, thereby manifesting an intriguing symmetry between the two asymptotic regimes.

gr-qc↗

arXiv2025

Echoes from the Minkowski-core spacetime

In this study, we construct a class of horizonless exotic compact objects (ECOs) with Minkowski core, classifying them as either photon sphere ECOs (PS ECOs) or photon sphere lacking ECOs (PL ECOs) based on photon sphere topology. Time domain analysis reveals that the dynamical evolution can be divided into three phases: the initial ringdown, the echo phase, and the final ringdown. The echo signals exhibit the periodic damping, with quantum effects significantly accelerating the echo dissipation and prompting an earlier transition to the long lived mode dominated phase. Furthermore, the QNM spectrum of the PS ECO exhibits fundamentally different behavior from that of BHs including the presence of long lived modes and the absence of overtone outbursts providing a clear spectroscopic signature distinguishing PS ECOs from BHs. This work is significant in providing new theoretical foundations and waveform features for identifying such quantum corrected ECOs, contributing critically to the understanding of quantum gravity effects.

gr-qc↗

arXiv2025

Gravitational waveforms from periodic orbits around a novel regular black hole

We explore potential quantum gravity signatures by studying periodic orbits and their GW emissions around a novel regular black hole (BH) featuring a Minkowski core. Using a rational number $q$, periodic orbits are classified, revealing that the deviation parameter $\alpha_0$ reshapes the bound-orbit region while preserving characteristic ``zoom-whirl" structures. Numerical kludge waveforms reveal detectable phase shifts and amplitude modulations induced by quantum gravity effects with radiation reaction breaking orbital periodicity. Faithfulness analysis demonstrates that larger $\alpha_{0}$ and $q$ enhance distinguishability from the Schwarzschild case, and a comparison with Hayward and quantum Oppenheimer-Snyder BHs shows their similar large-scale behaviors yield macroscopically indistinguishable orbits and waveforms.

gr-qc↗

arXiv2025

Capturing quantum phase transition in the ultraviolet region by holography

We reveal for the first time that ultraviolet (UV) observables can diagnose quantum phase transitions (QPTs). In a class of holographic models exhibiting metal-insulator transitions, we study two types of UV observables -- high-frequency conductivity and short-range entanglement. Remarkably, we find that the derivatives of these UV observables exhibit extrema near the quantum critical point. Analytical results show these critical behaviors arise from the deformation of the asymptotic bulk geometry. Moreover, these UV diagnostics show enhanced robustness to thermal fluctuations compared to typical infrared (IR) diagnostics, providing a clean method to identify quantum criticality at finite temperature. This work opens a new window for exploring quantum critical phenomena via UV physics in the laboratory.

hep-th↗

arXiv2025

Probing loop quantum effects through solar system experiments: observational signatures and parameter constraints

This study investigates quantum gravity effects within the framework of an effective loop quantum gravity (LQG) black hole model parameterized by $\zeta$, utilizing precision measurements from solar system experiments and astrophysical observations. We analyze three classical tests of general relativity (GR): (1) Light deflection constrained by very long baseline interferometry (VLBI) observations of quasar radio signals, (2) Shapiro time delay measurements from the Cassini mission, and (3) Mercury's perihelion precession determined by MESSENGER mission data. Additionally, we extend our analysis to Earth-orbiting LAGEOS satellites and the relativistic trajectory of the S2 star orbiting the Galactic Center supermassive black hole Sagittarius $\rm{A}^*$ (Sgr $\rm{A}^{*}$). Our multi-probe approach reveals that the tightest constraint on the LQG parameter comes from Mercury's perihelion precession, yielding an upper bound $\zeta \lesssim 10^{-2}$. These results establish new observational benchmarks for probing quantum gravity effects.

gr-qc↗

arXiv2024

Observational appearances of an inner extremal regular black hole illuminated by various accretion flows

This paper investigates the observational appearances of an inner extremal regular black hole(IERBH) illuminated by various types of accretion models. The study reveals that when the BH is illuminated by specific accretion flows, the effects of quantum gravity become more pronounced,significantly impacting key observational features such as the shadow radius, photon ring, and total observed intensity. Specifically, the introduction of a more realistic radially infalling spherical accretion flow further accentuates these differences. This dynamic flow results in a darker central region in the BH image due to the Doppler effect, which modulates the observed intensity based on the relative motion of the infalling matter. The shadow radius and total observed intensity are notably affected by the quantum correction parameters, providing additional signatures that distinguish regular BHs from their classical counterparts.

gr-qc↗