arXiv subjects

Yi Ling

Publications and source records attributed to Yi Ling.

At least 19 recordsLinked to original sources

arXiv2026

Static Vacuum Geometry Encodes Gravitational Collapse and Cosmology

We show that, within covariant Hamiltonian gravity in spherical symmetry, a prescribed one-parameter family of static vacuum geometries uniquely determines the local dynamics of gravitational collapse coupled to irrotational dust, despite the nonuniqueness of the underlying gravitational Hamiltonian. We further derive necessary and sufficient conditions under which the resulting dynamics admits a homogeneous and isotropic cosmological sector. These conditions establish a two-way correspondence between static vacuum geometries and modified Friedmann dynamics and impose a universal restriction on the spatial-curvature dependence of the latter. Our results provide a criterion for determining whether independently proposed black-hole and cosmological models can arise from a common covariant gravitational theory.

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arXiv2026

Global curvature control in a regular black hole with Minkowski core and inner-extremal horizon

We construct a static, spherically symmetric regular black hole with a Minkowski core, a non-extremal outer horizon, and a degenerate inner horizon with vanishing surface gravity. The spacetime exhibits two main features. First, in the large-mass regime with $r_+=2M$, the maximal Kretschmann scalar becomes nearly independent of the ADM mass and is mainly controlled by the inner-horizon radius $r_-$, providing a simple sufficient condition for the curvature to remain sub-Planckian everywhere. Second, the effective cubic zero of the metric function replaces the standard exponential near-horizon amplification with power-law behavior. A massless scalar test field shows that the geometric blueshift factor grows as $v^{3/2}$. Then, we use the double-null shell and Ori models to examine the corresponding effective mass dynamics. the nonlinear shell-crossing contribution decays at late times, while the Ori evolution with a Price-law ingoing flux keeps the internal Misner-Sharp mass bounded. In both descriptions, the late-time mass approaches $r_-/2$. The same inner-horizon scale therefore controls the global curvature bound and the finite mass scale reached by the shell dynamics.

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arXiv2026

Optical conductivity of holographic striped superconductors

Based on a holographic model exhibiting Mott-like insulating behavior on an ionic lattice, we construct a holographic striped superconductor (SSC), which is characterized by the interplay between the charge density wave (CDW) and superconductivity (SC). We present the phase diagram on the $e$-$T$ plane, where the SSC phase emerges within an intermediate window of $e$, revealing both cooperative and competitive relations between the CDW order and SC order. For small charge $e$, the system undergoes the phase transition from metallic phase to CDW phase, and then to SSC phase upon cooling; while for large $e$, it transitions from metallic phase to SC phase directly, and then to SSC phase. We compute the optical conductivity of the system for these two cases and demonstrate its distinct behavior. It turns out that the imaginary part of the conductivity exhibits a divergent behavior below the critical temperature $T_{\mathrm{SSC}}$ along both pathways, so that the superconductivity of SSC phase is justified for the first time in the holographic framework. Along the CDW-to-SSC pathway the pseudogap and the pinning effect are inherited from the CDW phase, whereas along the SC-to-SSC pathway the spontaneous stripe strongly suppresses the coherent normal-fluid channel while the superfluid pole is enhanced. In addition, we demonstrate the commensurate lock-in behavior of the striped superconductor in the $p$-$T$ diagram.

hep-th↗

arXiv2026

Spontaneous Scalarization of Brane Black Holes: Quantum-Enhanced Tachyonic Instabilities

We investigate the spontaneous scalarization of brane-localized charged black holes, focusing on the role of quantum-enhanced tachyonic instabilities. By solving the coupled bulk-brane equations numerically within the Einstein-DeTurck formulation, we construct fully backreacted static black hole solutions and map the system from the semi-classical limit to the strongly coupled quantum-dominated regime. We demonstrate that the holographic quantum effects, parameterized by $κ$, significantly modify the background geometry. Stability analysis, conducted via both effective potential diagnostics and quasinormal mode calculations, confirms that this geometric deformation deepens the negative well of the effective potential, thereby triggering a tachyonic instability. Integrating these results, we establish the global phase diagram of spontaneous scalarization in the $T_h/μ-κ$ parameter space. The results reveal that these quantum-enhanced instabilities promote scalarization by substantially raising the critical temperature, providing a clear quantitative signature of quantum effects on black hole hair formation.

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arXiv2026

Boundary mutual information in double holography

We consider a composite system where AdS$_3$ gravity is coupled to a flat heat bath and investigate the mutual information between two subregions on the intersection of the AdS$_3$ and bath, referred to as the boundary mutual information (BMI). The corresponding entanglement entropy is captured via quantum extremal surfaces (QES), which holographically be computed by a surface optimization algorithm based on ``Surface Evolver''. We focus on both connected and disconnected configurations of the quantum entanglement wedge (Q-EW) in the AdS$_3$ bulk and analyze the finite corrections to the BMI. Our numerical results reveal a phase transition of the BMI as the separation between two subregions increases. Furthermore, we find that the BMI can naturally be decomposed into two distinct components: a geometric term arising from the areas of the quantum extremal surfaces, and a correction term resulting from bulk quantum fields within the Q-EW. Interestingly, the geometric contribution always exceeds the total BMI, indicating a negative correction from the bulk matter fields. This negativity can be understood as the result of subtracting a greater contribution from quantum fields in the connected Q-EW than in the disconnected one. We also reproduce the negative contribution of bulk quantum fields to BMI within a random tensor network (RTN) toy model of double holography. Modeling the bulk as a highly mixed state entangled with a large bath leads to a volume-law bulk entropy. In the large bond-dimension limit, the geometric part of the BMI remains non-negative, while the bulk entropy contribution becomes non-positive when the Q-EWs merge.

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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.

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arXiv2026

Big bounce and black bounce in quasi-topological gravity

In the framework of quasi-topological (QT) gravity, we propose a novel model which is characterized by a bounce of the spacetime such that the singularity in standard general relativity can be avoided in both cosmological and black hole setups. Specifically, in the cosmological background, this model reproduces the modified Friedmann equation proposed in loop quantum cosmology, while in a black hole background, it produces a black bounce metric identical to that of the quantum Oppenheimer-Snyder (qOS) model. This model resolves the singularity presented in the qOS model as well as in QT gravity coupled to linear electromagnetic fields, and provides a unified, manifestly covariant framework for general spacetimes, from which both the modified Friedmann equation and the qOS black hole metric can be derived. Furthermore, it establishes a profound correspondence between the effective dynamics of loop quantum cosmology and the QT gravity theory, suggesting that certain quantum gravitational effects in loop quantum gravity can be captured by adding an infinite tower of higher-curvature corrections to the Einstein-Hilbert action.

gr-qc↗

arXiv2026

Exact Dynamical Regular Black Holes from Generalized Polytropic Matter

We present a class of exact, dynamical, and fully analytic solutions describing regular black holes formed via the gravitational collapse of matter obeying a generalized polytropic equation of state. Starting from a Vaidya-type geometry with a radially dependent mass function, we demonstrate that regularization of the Kiselev solutions can be achieved through a physically motivated modification of the energy density profile. This procedure leads to nonsingular spacetimes with a de~Sitter core and finite curvature invariants at the center. We show that the resulting matter content is naturally described by a generalized polytropic equation of state of the form $P=αρ-ζρ^γ$, where the polytropic index $γ$ is uniquely determined by the regularization scheme. Within this framework, we obtain exact dynamical generalizations of several well-known regular black hole solutions, including the Hayward and Bardeen spacetimes, as particular cases corresponding to specific values of the polytropic parameters. Remarkably, the requirement that the equation of state remains coordinate independent imposes a universal constraint relating the regularization scale to the mass function, which in turn guarantees the existence of a regular de~Sitter core with a curvature scale independent of the black hole mass. Our results provide a unified analytic description of Hayward-like and Bardeen-like black holes emerging from gravitational collapse, offering a consistent effective-matter interpretation rooted in generalized polytropic matter.

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arXiv2026

The holographic Fermions over the ionic lattice with CDW

We study the holographic Fermion as a probe over the background with ionic lattice, which may undergo a phase transition with the development of charge density wave by the spontaneous breaking of the translational symmetry. We focus on the structure of the Fermi surface within different Brillouin zones and demonstrate how the presence of CDW in the background affects the formation of the band gap in the momentum space. Specifically, we find the formation of the CDW enhances the amplitude of spectral function as well as the momentum of the Fermi surface. Furthermore, we are concerned with the change of the Fermi surface with the doping parameter as well as the lattice amplitude. Interestingly, we find that the radius of the Fermi surface expands with the increase of the doping parameter and finally may cross the first Brillouin zone. Additionally, the width of band gap becomes larger with the increase of the lattice amplitude as well, which is consistent with the observation in condensed matter experiments.

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arXiv2025

Linking interior curvature to observable shadows: A case study of nonsingular black holes

We establish a direct connection between the interior curvature structure of nonsingular black holes (BHs) with a Minkowski core and their observable optical signatures. By classifying these spacetimes into three fundamental types, Type I (Kretschmann scalar K_max increasing with mass M), Type II (mass-independent K_max), and Type III (K_max decreasing with M), we demonstrate how subtle variations in the core geometry imprint distinguishable features on the BH shadow. A detailed analysis of photon dynamics reveals that the parameters α and n, which control the deviation from Schwarzschild geometry and the radial decay of the regularizing factor, respectively, systematically alter the properties of the photon sphere. These intrinsic geometric differences propagate outward: for fixed parameters, Type III BHs, with the most compact photon sphere, produce the smallest and brightest shadows, whereas Type I BHs yield the largest and dimmest ones. Shadow computations under both static and infalling spherical accretion models confirm that the curvature-based classification directly corresponds to observable differences. Critically, Type III BHs exhibit the strongest sensitivity to parameter variations, making them optimal probes for constraining the underlying spacetime geometry. Our work reveals that even among nonsingular BHs sharing the same asymptotic core, differences in internal curvature are reflected in the shadow morphology, thereby providing a new pathway to test quantum-gravity-inspired models using upcoming high-resolution observations.

gr-qc↗

arXiv2025

Gravity induced entanglement of multiple massive particles with large spin

We investigate the generation rate of the quantum entanglement in a system composed of multiple massive particles with large spin, where the mass of a single particle can be split into multiple trajectories by a generalized Stern-Gerlach interferometer. Taking the coherent spin states (CSS) as the initial state and considering the gravitational interaction due to Newtonian potential, we compute the generation rate of the entanglement for different configurations of the setup. Explicitly, the optimal polar angles of the spin are found numerically for systems with three and four particles, respectively. We conclude that the amount of the entanglement increases with the number of particles as well as the spin, and the configuration of the prism with a particle at the center generates the best rate of the entanglement.

gr-qc↗

arXiv2025

The second-order quasi-normal modes for AdS black branes

We investigate second-order gravitational perturbations in asymptotically AdS black branes, developing a gauge-invariant framework to compute the amplitude ratio between quadratic and linear quasi-normal modes. Our analysis reveals resonant divergences of this ratio when the summed frequencies of two source modes coincide with the frequency of a third mode. These divergences are shown to manifest as poles in three-point fully retarded correlators of the energy-momentum tensor in the holographically dual quantum field theory, establishing a concrete connection between bulk gravitational nonlinearities and observables in the dual boundary theory. Our findings contribute to the understanding of nonlinearity in quantum many-body systems while deepening the holographic dictionary between spacetime dynamics and quantum correlations.

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.

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arXiv2025

Investigating the shadows of new regular black holes with a Minkowski core: Effects of spherical accretion and core type differences

We investigated the shadows and optical appearances of a new type of regular black holes (BHs) with a Minkowski core under various spherical accretion scenarios. These BHs are constructed by modifying the Newtonian potential based on the minimum observable length in the Generalized Uncertainty Principle (GUP). They correspond one-to-one with traditional regular BHs featuring a de-Sitter (dS) core (such as Bardeen/Hayward BHs), characterized by a quantum gravity effect parameter ($α_0$) and spacetime deformation factor ($n$). We found that the characteristic parameters give rise to some novel observable features. For these new BHs, both the shadow and photon sphere radii decrease with the increase in $α_0$, while the observed specific intensity increases. Conversely, as n increases, the shadow and photon sphere radii increase, while the observed specific intensity decreases. Under different spherical accretion scenarios, the shadows and photon sphere radii remain identical; however, the observed specific intensity is greater under static spherical accretion than under infalling spherical accretion. Additionally, we found that these regular BHs with different cores exhibit variations in shadows and optical appearances, particularly under static spherical accretion. Compared with Bardeen BH, the new BHs exhibit a lower observed specific intensity, a dimmer photon ring, and smaller shadow and photon sphere radii. Larger values of $α_0$ lead to more significant differences, and a similar trend was also observed when comparing with Hayward BH. Under infalling spherical accretion, the regular BHs with different cores exhibit only slight differences in observed specific intensity, which become more evident when $α_0$ is relatively large.

gr-qc↗

arXiv2025

Symmetric black-to-white hole solutions with a cosmological constant

For a system with a Hamiltonian constraint, we demonstrate that its dynamics is invariant under different choices of the lapse function, regardless of whether the Hamiltonian incorporates quantum corrections. Applying this observation to the interior of black-to-white holes, we analyze its dynamics with different choices of the lapse function. The results explicitly show that the leading-order expansion of both metrics proposed by Rovelli et al. (Class. Quant. Grav. \textbf{35}, 225003 (2018); Class. Quant. Grav. \textbf{35}, 215010 (2018)) and Ashtekar et al. (Phys. Rev. Lett. \textbf{121}, 241301 (2018); Phys. Rev. D \textbf{98}, 126003 (2018)) exhibit identical behavior near the transition surface. Therefore, in this sense the black-to-white hole model proposed by Rovelli et al., (Class. Quant. Grav. \textbf{35}, 225003 (2018); Class. Quant. Grav. \textbf{35}, 215010 (2018)) may be interpreted as a coarse-grained version of the solution within the framework of loop quantum gravity. The black-to-white hole solutions with exact symmetry between the black hole and white hole regions are constructed by appropriately fixing the quantum parameters in the effective theory of loop quantum gravity. This approach circumvents the issue of amplification of mass, which could arise from a mass difference between the black hole and white hole, and provides a way to link the solutions obtained by minisuperspace quantization to those in the covariant approach. Finally, the black-to-white hole solutions with a cosmological constant are constructed. The numerical solutions for the interior of the black-to-white hole with a cosmological constant are obtained, and their symmetric behavior is also discussed.

gr-qc↗

arXiv2025

Correspondence between grey-body factors and quasinormal modes for regular black holes with sub-Planckian curvature

We investigate the quasi-normal modes (QNMs) under the gravitational field perturbations and the grey-body factors for a class of regular black holes with sub-Planckian curvature and Minkowski core. Specifically, we compute the QNMs with the pseudospectral method and the WKB method. It is found that as the deviation parameter of the regular black hole changes, the trajectory of the QNMs displays non-monotonic behavior. Then we compute the grey-body factors with the WKB method and compare them with the results obtained by the correspondence relation recently revealed in [1]. We find the discrepancy exhibits minimor errors, indicating that this relation is effective for computing the grey-body factors of such regular black holes.

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arXiv2024

The commensurate state and lock-in in a holographic model

We study a holographic model in which the striped structure of charge density is spontaneously formed over an ionic lattice which breaks the translational symmetry explicitly. The effect of commensurate lock-in between the spontaneous stripes and the ionic lattice is observed when the lattice amplitude is large enough. We investigate the optical conductivity as a function of frequency in commensurate state and compare its characteristics during the phase transition from metallic phase to insulating phase. Notably, we find that the DC resistivity in lock-in state increases algebraically with lowering temperature, which is in line with the phenomenon observed in the holographic model for simulating the experimental behavior of Mott insulator in [Nature Phys. 14, no.10, 1049-1055 (2018)]. In addition, at lower temperature the pinning effect is observed for both unlock-in and lock-in states. This holographic model successfully demonstrates the commensurate lock-in signatures, and provides more information for understanding the interplay between ionic lattices and electronic lattices by holography.

hep-th↗

arXiv2024

Holographic striped superconductor with ionic lattice

We construct a holographic model to study the striped superconductor on ionic lattices. This model features a phase diagram with three distinct phases, namely the charge density wave (CDW) phase, ordinary superconducting phase (SC) and the striped superconducting phase (SSC). The effect of the ionic lattices on the phase diagram is investigated in detail. First, due to the periodic nature of the background, different types of CDW solutions can be found below the critical temperature. Furthermore, with the increase of the lattice amplitude these solutions are locked in different commensurate states. Second, we find that the critical temperature of CDW phase decreases with the increase of the lattice amplitude, while that of the SC phase increases. Additionally, the background solutions are obtained for different phases, and it is verified that the SSC phase has the lowest free energy among all three phases.

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