arXiv subjects

Hadyan Luthfan Prihadi

Publications and source records attributed to Hadyan Luthfan Prihadi.

16 recordsLinked to original sources

arXiv2026

Physical properties of compact star-like systems harboring traversable wormholes: Effects of chaotic magnetic fields and anisotropic matter

We formulate exotic compact objects in form of compact star-like systems harboring traversable wormhole (CSSTW) with chaotic magnetic field and pressure anisotropy of the neutron fluid. The wormhole is traversable regardless of whether anisotropy of the neutron fluid and/or magnetic fields are included. For magnetized configurations, the resulting CSSTW can become extremely massive, with ADM masses exceeding $8\,M_\odot$, and can exhibit large surface redshifts exceeding $\mathcal{Z} \simeq 1.5$. The system can also reach the ultracompact regime, which allows us to calculate echo time that might be produced by the systems. Echo times of considered CSSTW vary depending on the chaotic magnetic field configuration and fluid anisotropy. For non-magnetized configurations, the gravitational-wave echo time is of the order of $10^{-2}-10^{-1}$ ms. For the magnetized configurations, however, it ranges from the order of $10^{-1}$ $μ$s $-10^{-1}$ ms Moreover, we derive an explicit expression for the echo time as a function of uniform magnetic field. The resulting relation shows that the echo time decreases as the magnetic field strength increases. The stability analysis of radial perturbations shows that the ultracompact non-magneized CSSTW are prone to be unstable. For magnetized CSSTW, all considered configurations with a surface magnetic field of $B_s=10^{15}$ G are stable.

gr-qc↗

arXiv2026

Kerr/CFT Traversable Wormhole with Fermionic Double-Trace Deformation

The construction of a traversable wormhole with double-trace deformation has been achieved so far by using boson fields as the perturbation. In this work, we study double-trace deformation with fermion fields in the two-sided Kerr background to open a traversable wormhole. We construct the fermionic double-trace deformation within the Kerr/CFT framework. We consider the near-horizon, near-extremal Kerr geometry, which is dual to a conformal field theory. The lack of fermionic superradiance let us describe the wormhole at every region, even at the off-axis region where bosonic field experiences instability due to superradiance. By choosing a certain coupling between the left and right boundaries, the two-point function is modified, and its first order correction contributes the negative energy to open the wormhole. The wormhole is most traversable when the perturbation is turned on at early times, with opening that depends on the mode's frequency, the black hole temperature, and the fermion mass. At late times, the average null energy has damped oscillation behavior until eventually reaches zero. Wormhole with lower temperature have less traversability and it is completely closed at extreme limit. The same traversability can also be reproduced by using eikonal method. On the other hand, rotation and the number of fields involved in the deformation can increases the upper bound on information transfer up to the order of the entropy. Additionally, symmetrical effective potential bumps connected by the wormhole can produce observable echoes. We find that the echo time delay cannot exceed the scrambling time of the black hole.

hep-th↗

arXiv2026

Predicting Multipartite Entanglement in Quantum Circuits using Transformer

Multipartite entanglement is a critical property of parameterized quantum circuits (PQCs), particularly for near-term hybrid quantum-classical algorithms, as it characterizes their ability to generate highly entangled states. However, measuring entanglement remains computationally expensive because conventional Monte Carlo sampling scales unfavorably with system size. To overcome this challenge, we introduce a graph-based transformer surrogate that predicts both the first-order Meyer-Wallach measure ($Q_1$) and the second-order Scott measure ($Q_2$), resolving entanglement structures indistinguishable under $Q_1$ alone. Our central contribution is the qubit-interconnected graph (QIG) encoding for transformers, where each node represents a qubit and weighted adjacencies record entangling-gate multiplicities. Fused with a gate-level DAG encoder, this yields the QIG-Fusion model. Evaluated on 50,000 circuits spanning 4- to 8-qubit systems across a ten-seed protocol, QIG-Fusion achieves an RMSE as low as 0.037 ($Q_2$) and 0.038 ($Q_1$), with a Spearman rank correlation up to 0.95. This framework significantly reduces the computational cost of Quantum Architecture Search (QAS), enabling efficient entanglement estimation for large-scale PQCs.

quant-ph↗

arXiv2026

Pauli Weight Hamiltonian Term Selection for Optimized Machine Learning Based Quantum Error Mitigation

Machine learning provides a scalable solution for quantum error mitigation. However, the selection of appropriate Pauli strings for inclusion in training data remains a challenge. Current methods rely on heuristic or uniform random sampling, requiring data for every Pauli string in the Hamiltonian, a process that scales linearly with measurements and grows with system size. To address this, we introduce quantum error mitigation with prior knowledge of Pauli weights (Pauli weight quantum error mitigation (Pi-QEM)), a systematic framework that selects training observables based on Pauli weight. By leveraging the relationship between variance and locality in parameterized quantum circuits, Pi-QEM trains on a small subset of dominant, low-weight Pauli strings. In numerical simulations of molecular systems on a noisy IBM quantum backend, Pi-QEM reduces ground-state energy estimation error by up to 34.01% using just a single dominant local observable, offering an efficient, scalable pathway for high-precision error mitigation on NISQ devices.

quant-ph↗

arXiv2026

Traversable wormhole with double trace deformations via gravitational shear and sound channels

We investigate how non-local gravitational couplings from double trace deformation between two asymptotic boundaries of an AdS$_5$ black brane can lead to the violation of the Averaged Null Energy Condition (ANEC). The first-order gravitational perturbations backreact with the background metric at second-order, creating a wormhole opening in the context of Gao-Jafferis-Wall traversable wormhole protocol. The wormhole becomes traversable in both the gravitational shear and sound channels within the hydrodynamic approximation. This shows that dynamical metric perturbations can facilitate information transfer in a purely gravitational setting, with the emergence of $G_{\text{N}}$ indicating the gravitational origin. For the shear channel, we consider three different coupling configurations, whereas for the sound channel, we vary both the speed of sound and the attenuation constant, as these parameters control the wormhole traversability. Furthermore, we obtain late-time power-law factor in the ANEC using fitting function and present a generalization that applies to both shear and sound channels. Due to its propagating nature, the sound channel exhibits late-time power-law remnants at low sound speed similar to the vector diffusive probes, but it prefers an exponential decay at higher sound speed similar to the scalar non-diffusive probes, as the power-law exponent weakened with increasing sound speed. For superluminal sound channels, the wormhole opens for an extremely brief duration at late insertion times, rendering it non-

hep-th↗

arXiv2026

Holographic timelike entanglement and subregion complexity with scalar hair

We investigate the holographic timelike entanglement entropy (HTEE) and timelike subregion complexity of a thermal CFT$_d$ deformed by a relevant scalar operator $ϕ_0$, dual to a hairy black hole in AdS$_{d+1}$. We employ the prescription of merging spacelike and timelike surfaces at the interior, constructing an extremal surface homologous to a boundary timelike subsystem with a time interval $Δt$. Consequently, this deformation breaks the invariance of the imaginary component of HTEE observed in pure AdS$_3$ and BTZ geometry, introducing a nontrivial dependence on $Δt$. At small $Δt$, we derive analytical expressions that are in agreement with numerical results, and observe partial consistency with analytic continuation to temporal or spacelike entanglement entropy at the level of the near-boundary expansion. However, analytic continuation of CFT temporal entanglement entropy fails to reproduce the HTEE calculations under boundary deformation, even in $d=2$. Furthermore, we extend the numerical calculations to higher dimensions ($d=3$). In addition, we study holographic timelike subregion complexity within the complexity=volume conjecture and find that it remains real-valued, providing a complementary geometric probe of the black hole interior. In particular, for the BTZ black hole, we analytically show that the UV-finite term of the subregion complexity receives its entire contribution from the interior region alone.

hep-th↗

arXiv2025

Stationary Solution to Charged Hairy Black Hole in AdS4: Kasner Interior, Rotating Shock Waves, and Fast Scrambling

We consider a stationary solution of a charged black hole with scalar hair in AdS$_4$, where the scalar field is coupled to a $U(1)$ Maxwell gauge field. Near the singularity, the spacetime transitions into a more general Kasner geometry. The black hole is then injected with rotating and charged gravitational shock waves in the Dray-'t Hooft solution. These shock waves lengthen the wormhole connecting the two asymptotic boundaries, thereby disrupting the correlations between them. The correlation, quantified by the quantum mutual information between subregions on the left and right boundaries, vanishes at a characteristic timescale known as the scrambling time, which depends logarithmically on the black hole entropy. The mutual information is computed holographically using the Ryu-Takayanagi prescription for entanglement entropy. We investigate how the rotation and charge of both the black hole and the shock waves affect chaotic properties such as the scrambling time delay and the Lyapunov exponent. The interaction between the charges of the black hole and the shock waves introduces a delay in the scrambling process. We find that as the strength of the boundary deformation increases, both the Lyapunov exponent and the scrambling time delay decrease monotonically. Furthermore, the angular momentum of the shock waves enhances both the Lyapunov exponent and the scrambling time delay.

hep-th↗

arXiv2025

Scrambling in charged hairy black holes and the Kasner interior

We analyze how the axion parameter, the Einstein-Maxwell-Scalar (EMS) coupling constant, and the charge density affect the chaotic properties of a charged hairy black hole, as characterized by the quantum Lyapunov exponent. We inject charged shock waves from the asymptotic boundary and compute the out-of-time-ordered correlators (OTOCs). Due to the relevant deformation in the boundary theory induced by a bulk scalar field, the bulk solution flows to a more general Kasner spacetime near the black hole singularity. We examine the behavior of chaotic parameters, including the Lyapunov exponent, butterfly velocity, and scrambling time delay, under this deformation. We find that as the deformation parameter increases, the ratio of the quantum Lyapunov exponent to the surface gravity decreases. For sufficiently large deformation, the Lyapunov exponent in the deformed geometry can exceed that of the axion Reissner-Nordstrom case. We observe that boundary deformation generally reduces the scrambling time delay, with the EMS coupling having a significant effect on the delay. These results provide further insight into the role of boundary deformations in modifying chaotic properties in charged hairy black holes.

hep-th↗

arXiv2025

Scalar tidal response of static and rotating black holes in anti-de Sitter spacetime

In this work, we investigate the tidal response of both static and rotating black holes in anti de-Sitter spacetime. We perform the neutral scalar field perturbation for Schwarzschild and Kerr black holes. On the other hand, charged scalar field are used for perturbing Reissner-Nordstrom and Kerr-Newman black holes. We find that the tidal Love number for all black holes are always nonvanishing due to the presence of cosmological constant. In contrast, tidal dissipation can vanish for certain conditions depending on the scalar field's frequency and the black hole's parameters.

gr-qc↗

arXiv2025

Positive Mass in Scalar-Torsion Holography

We investigate the holographic renormalization of scalar-torsion gravity in a four-dimensional bulk spacetime with non-minimal derivative coupling. The asymptotic behavior of the static equations leads to an anti-de Sitter geometry for negative cosmological constants, allowing for a holographic interpretation via the AdS/CFT correspondence. The existence of unique solutions throughout the bulk is addressed. We study the effect of the non-minimal coupling parameter on the conformal dimension and the expectation value of the dual scalar operator, showing that the effective bulk mass can be tuned through the non-minimal coupling. Our results provide a formalism for finding non-tachyonic bulk scalar fields which vanish at the boundary.

hep-th↗

arXiv2024

Localized chaos due to rotating shock waves in Kerr-AdS black holes and their ultraspinning version

The butterfly velocity of four-dimensional rotating charged asymptotically AdS black hole is calculated to probe chaos using localized rotating shock waves. In this work, we obtain the angular momentum dependence of the butterfly velocity due to rotation in the shock wave probes. In general, the angular momentum $\mathcal{L}$ of the shock waves increases the butterfly velocity. The localized shocks also generate butterfly velocities which vanish when we approach extremality, indicating no entanglement spread near extremality. One of the butterfly velocity modes is well bounded by both the speed of light and the Schwarzschild-AdS result, while the other may become superluminal. Aside from the logarithmic behavior of the scrambling time which indicates chaos, the Lyapunov exponent is also positive and bounded by $κ=2πT_H/(1-μ\mathcal{L})$. The Kerr-NUT-AdS and Kerr-Sen-AdS solutions and their ultraspinning versions are used as examples to attain a better understanding of the chaotic phenomena in rotating black holes, especially those with extra conserved charges.

hep-th↗

arXiv2024

Black-Body Radiation in a Uniformly Accelerated Frame

We derive Planck's radiation law in a uniformly accelerated frame expressed in Rindler coordinates. The black-body spectrum is time-dependent by its temperature and Planckian at each instantaneous time, but it is scaled by an emissivity factor that depends on the Rindler spatial coordinate and the acceleration magnitude. The observer in an accelerated frame will perceive the black-body as black, hyperblack, or grey, depending on its position with respect to the source (moving away or towards), the acceleration magnitude, and the case of whether it is accelerated or decelerated. For an observer accelerating away from the source, there exists a threshold on the acceleration magnitude beyond which it stops receiving radiation from the black-body. Since the frequency and the number of modes in Planck's law evolve over time, the spectrum is continuously red or blue-shifted towards lower (or higher) frequencies as time progresses, and the radiation modes (photons) could be created or annihilated, depending on the observer's position and its acceleration or deceleration relative to the source of radiation.

gr-qc↗

arXiv2023

Chaos and fast scrambling delays of dyonic Kerr-Sen-AdS$_4$ black hole and its ultra-spinning version

The scrambling time and its delay are calculated using holography in an asymptotically AdS black hole solution of the gauged Einstein-Maxwell-Dilaton-Axion (EMDA) theory, the dyonic Kerr-Sen-AdS$_4$ black hole, perturbed by rotating and charged shock waves along the equator. The leading term of the scrambling time for a black hole with large entropy is logarithmic in the entropy and hence supports the fast scrambling conjecture for this black hole solution, which implies that the system under consideration is chaotic. We also find that the instantaneous minimal Lyapunov index is bounded by $κ=2πT_H/(1-μ\mathcal{L})$, which is analogous to the surface gravity but for the rotating shock waves, and becomes closer to equality for the near extremal black hole. For a small value of the AdS scale, we found that the Lyapunov exponent can exceed the bound for a large value of $\mathcal{L}$. Due to the presence of the electric and magnetic charge of the shock waves, we also show that the scrambling process of this holographic system is delayed by a time scale that depends on the charges of the shock waves. The calculations also hold for the ultra-spinning version of this black hole. The result of this paper generalizes the holographic calculations of chaotic systems which are described by an EMDA theory in the bulk.

hep-th↗

arXiv2023

Replica Trick Calculation for Entanglement Entropy of Static Black Hole Spacetimes

We calculate the entanglement entropy between two (maximally-extended) spacetime regions of static black hole, seperated by horizon. As a first case, we consider the Schwarzschild black hole, and then we extend the calculations to the charged Reissner- Nordstrom and Schwarzschild-de Sitter black holes with more than one horizon. The case for static and spherically-symmetric solution to the more general F (R) gravity is also considered. The calculation of the entanglement entropy is performed using the replica trick by obtaining the explicit form of the metric which corresponds to the replica spacetime for each black hole under consideration. The calculation of static and spherically-symmetric black holes result in the entanglement entropy that matches the Bekenstein-Hawking area law entropy.

gr-qc↗

arXiv2021

Fluctuations and non-Gaussianity in de Sitter spacetime from holographic entanglement entropy

Using entanglement in dS/CFT correspondence, we show that a 4-dimensional de Sitter spacetime in the bulk fluctuates. We calculated the fluctuations of the entanglement entropy, which backreacts with the geometry of the bulk spacetime indicated by the fluctuations of the horizon radius. The variance of the fluctuations is suppressed by $G_N$ and multiplied by $H_{dS}^2$. Therefore, it will be more significant during the primordial era where it is also well described by de Sitter geometry. We also show that the distribution of the fluctuations is also skewed with the local non-linearity parameter is in the order of $f_{NL}\sim\mathcal{O}(1)$ and we present the probability density function with corrections up to $σ_Φ^3$.

hep-th↗

arXiv2020

Long-range correlation of CMB temperature fluctuations from the holographic entanglement entropy

In this paper, we define the holographic multipartite entanglement entropy for $N$ separated subsystems living in a compact $\text{CFT}_d$ space-time. In a large $N$ limit, we find that the first-order holographic entanglement entropy perturbation is proportional to the change in the length of the subsystem and it has symmetric (Gaussian) distribution property. From that finding, we propose to construct two-point correlation functions of holographic entanglement entropy fluctuations analogous to the one that is used in the cosmic microwave background (CMB) temperature fluctuations analysis. Using the first law of thermodynamics, we may correlate tiny changes in entanglement entropy with the temperature fluctuations. By comparing with Planck 2018 CMB data from $j=2$ to $j=2499$ where $j$ denotes the multipole moment, we extract the distribution of the entangling region size that corresponds to the temperature fluctuations. Since the distribution of the entangling region size can be interpreted as the CMB temperature fluctuations, we conclude that entanglement might play a role in the quantum aspects of cosmology.

hep-th↗