arXiv subjects

Tong Liu

Publications and source records attributed to Tong Liu.

At least 19 recordsLinked to original sources

arXiv2026

Breaking Fault Lines: Unifying TEE-Assisted BFT Consensus in Partially Trusted Worlds

This paper revisits TEE-assisted BFT under a universal partial-TEE model, where an arbitrary subset of replicas execute inside TEEs while the remaining replicas operate without hardware trust guarantees. We show that heterogeneous trust changes the structure of quorum formation and fault tolerance. In particular, we derive a tight resilience bound f < max {n/3, m/2}, where n is the total number of replicas and m is the number of TEE-enabled replicas. The result reveals a sharp threshold phenomenon: TEEs improve fault tolerance only once they exceed two-thirds of the deployment. Guided by this characterization, we introduce two protocol principles: (1) a dual-quorum construction that safely combines TEE-only and mixed quorums, and (2) a TEE-leader fast path that leverages hardware-enforced non-equivocation to reduce both consensus and view-change latency. We realize these ideas in Raftel, which is, to our knowledge, the first HotStuff-style BFT protocol designed explicitly for arbitrary partial-TEE deployments, and in chained-Raftel, a pipelined variant that further accelerates mixed-trust execution. We implement both protocols atop Intel SGX and evaluate them in LAN and WAN environments. Our results show that Raftel achieves up to 625 TPS with sub-670 ms latency in WAN settings, outperforming HotStuff by up to 308 TPS in throughput while approaching the performance of fully TEE-assisted protocols.

cs.DC↗

arXiv2026

Tunable topological enhancement of covariant quantum Fisher information via non-Bloch skin effect in non-Hermitian SSH lattices

The covariant quantum Fisher information (CQFI) has recently been established as the ultimate precision benchmark for pseudo-Hermitian sensors [Phys. Rev. Lett. 136, 080802 (2026)], yet existing analyses are limited to single-mode systems. Here we extend the CQFI formalism to multi-mode non-Hermitian Su-Schrieffer-Heeger lattices and reveal tunable topological enhancement enabled by the non-Hermitian skin effect (NHSE). Under open boundary conditions, the NHSE deforms the conventional Brillouin zone into a generalized Brillouin zone of radius r = exp(\k{appa}), where \k{appa} denotes the non-Bloch decay rate. While the total CQFI scales linearly with system size N, its prefactor depends critically on \k{appa}, yielding an enhancement factor E(N) = F_OBC / F_PBC that exceeds 30 for N ~ 30, substantially outperforming periodic-boundary sensors. The enhancement is robust against moderate local disorder and supports multi-parameter estimation, with the joint Cram\'er-Rao bound reduced by up to 15 orders of magnitude. These findings establish a spatial-domain mechanism for quantum metrology that complements time-domain strategies and is experimentally accessible using topoelectrical circuits, photonic lattices, and superconducting circuits with current technology.

quant-ph↗

arXiv2026

Reliable LLM-Generated Programs for High-Energy Physics Experiments through Graph-Grounded Software Knowledge

Extracting physics information from modern particle-physics experiments requires multistage analyses implemented on top of large and highly interconnected software ecosystems. General-purpose large language models (LLMs) often produce unreliable programs for such tasks because a user request alone rarely specifies the required APIs, dependencies, and usage conventions. We organize these software relations before generation and retrieve task-relevant knowledge at inference time. Using the open-source ROOT framework as a representative and reproducible testbed, we evaluate a complete grounding system that combines hybrid retrieval over a heterogeneous software knowledge graph, skill-selected workflow examples, and execution-guided repair. On a benchmark of 275 ROOT tasks, grounding improves first-attempt execution from 58.5% to 76.0% under Claude Code orchestration and from 51.3% to 64.0% under standalone orchestration. Final success increases from 90.5% to 96.0% and from 78.9% to 90.9%, respectively, while the average generation cost per successful task increases by only 1.3% and 3.2%. The gains persist under a strong coding agent, indicating that explicit software knowledge remains valuable even when agentic scaffolding is already in place. Because the method captures software relations common to large codebases rather than facts specific to ROOT or a particular model, it should transfer to other experiment frameworks and proprietary software, especially where documentation is sparse or internal dependencies are complex.

cs.SE↗

arXiv2026

Relativistic Modeling for Solid Earth Tide Estimation via Space-to-Ground Clock Comparison

With the rapid development of modern atomic clock technology, their unprecedented precision elevates them from timekeeping tools to gravitational potential sensors, thereby fostering the highly interdisciplinary field of Relativistic Geodesy. Given the potential for high-precision clock networks to detect periodic gravitational variations, it is imperative to assess their capability to invert solid Earth tide parameters via space-to-ground links in the presence of complex observational noise. To this end, we incorporate Earth's gravitational potential, direct lunisolar tidal potentials, and solid Earth tide effects into a high-precision relativistic framework for space-to-ground clock comparisons. By employing a three-link Doppler cancellation configuration to isolate the target signal, we perform numerical simulations for an inclined geosynchronous orbit satellite to analyze the effects of clock instability and colored precise orbit determination errors on parameter extraction. Our findings reveal that while high orbital altitudes cause severe collinearity between individual Love numbers, an effective parameter combining the $h_2$ and $k_2$ Love numbers successfully converges to a stable estimate within a 30-day continuous observation window. Furthermore, sensitivity analysis demonstrates that extraction accuracy is currently limited by clock stability rather than radial precise orbit determination errors.

gr-qc↗

arXiv2026

Symmetry Origins of the Field-Free Superconducting Diode Effect in the Kagome Superconductor CsV$_3$Sb$_5$

Field-free superconducting diode effects require both inversion-symmetry breaking and an internal time-reversal-symmetry (TRS) breaking field, making them sensitive probes of hidden order in superconductors. In centrosymmetric kagome AV$_3$Sb$_5$, the inversion symmetry generally should generally preclude the observation of the superconducting diode effect. Furthermore, though TRS breaking has been reported in the superconducting regime of CsV$_3$Sb$_5$, whether it is generated by superconductivity or inherited from charge-density-wave (CDW) order remains unresolved. Here we show that pristine CsV$_3$Sb$_5$ devices exhibit no intrinsic field-free superconducting diode effect, whereas surface oxidation or asymmetric etching activates a large nonreciprocal supercurrent. Moreover, the response is stochastic, with sweep-dependent polarity and magnitude, indicating metastable TRS-breaking domain configurations. Small out-of-plane magnetic fields stabilize the superconducting diode response, consistent with field selection of such domains. Finally, when long-range CDW order is suppressed by Ti doping, the SDE disappears. Our results establish the symmetry requirements for the field-free SDE in CsV$_3$Sb$_5$, reveal its stochastic domain-controlled character, and link superconducting-state TRS breaking to CDW-related order.

cond-mat.supr-con↗

arXiv2026

The Continuum Model for Uniaxially Strained Bilayer Graphene Moir\'e Systems

We construct a continuum model for a one-dimensional moir\'e superlattice formed by stretching one layer of AB-stacked bilayer graphene along the x direction by a factor s. Following the spirit of the Bistritzer-MacDonald model for twisted bilayer graphene, we treat the interlayer coupling as hopping between several Dirac points. At a critical stretch factor s ~ 1.018 the two bands near the Fermi level touch, forming two degeneracy points along the k_y direction. This gap closing is accompanied by a topological phase transition, in which the Chern number changes from 1 to -1, and by a sign change of the Berry-curvature dipole, which we propose can be detected through the nonlinear Hall effect. We find that uniaxial strain modulates inter-Dirac-valley coupling, which drives band gap collapse and subsequent topological number inversion. This opens a route to engineer topological transport and quantum anomalous Hall effects via strain engineering of moir\'e heterostructures.

cond-mat.mes-hall↗

arXiv2026

Quasi-periodic Eruptions from Recurrent Satellite Black Hole Transits through Magnetized Galactic Nucleus Accretion Disks

Quasi-periodic eruptions (QPEs) are recurrent soft X-ray flares from galactic nuclei, but their origin remains uncertain. The delayed ultraviolet (UV) counterpart detected in Ansky provides a new constraint on viable models. We present a two-channel model in which a satellite black hole (sBH) repeatedly crosses a nuclear accretion disk threaded by a large-scale magnetic field. Gravitational focusing and dynamical drag generate hot, optically thick ejecta whose expansion and photon diffusion power the soft X-ray QPE. For fiducial Bondi-scale parameters, the model yields a characteristic X-ray duration of $\sim10^3\ \mathrm{s}$ and luminosity of $\sim10^{42}\ \mathrm{erg\,s^{-1}}$; at lower orbital inclinations, the duration extends to the day-long scale observed in Ansky. Simultaneously, the sBH motion compresses and bends the background magnetic field, triggering in-disk reconnection. The dissipated energy then emerges after photon diffusion as a broader, delayed UV response. The resulting thermal power is comparable to the variable UV luminosity of Ansky. Unfavorable magnetic fields or diffusion times longer than the QPE recurrence period can weaken or smear out the UV signal, potentially explaining the lack of clear UV counterparts in other QPE sources.

astro-ph.HE↗

arXiv2026

Multi-Feature Riemannian Hypergraph for Online Test-Time Adaptation of Motor Imagery Brain-Computer Interface

In clinical motor imagery brain-computer interface (MI-BCI) decoding, cross-day transferability and online operation remain two critical challenges. Hypergraphs can improve transferability by capturing higher-order sample relationships, yet existing hypergraph-based methods for online emotion recognition neglect the cross-day benefits of Riemannian geometry widely adopted in EEG transfer learning. To bridge this gap, we propose the Multi-feature Riemannian Hypergraph (MRieHy), a framework tailored for online test-time adaptation in MI-BCI decoding that leverages Riemannian geometry to strengthen cross-day transferability. MRieHy first computes Riemannian means of covariance matrices from cross-day training data to align multi-day distributions. It then constructs a hypergraph over covariance matrices using Riemannian distance, complemented by a second hypergraph over deep features built with cosine similarity. The two hypergraphs are fused via adaptively learned combination weights, jointly optimized with the label projection matrices. During online testing, MRieHy maintains a first-in-first-out buffer of recent samples, performs Riemannian alignment on the buffered data, and decodes with the learned hypergraph. Extensive experiments on a private four-class ECoG dataset and two public four-class EEG datasets validate that MRieHy achieves notable performance gains over state-of-the-art baselines.

cs.LG↗

arXiv2026

A statistical relation of energy injection plateaus in multi-band afterglows of gamma-ray bursts

The origin of the plateau phase in gamma-ray burst (GRB) afterglows remains under debate, with the energy injection model being one of the most competitive explanations. If the plateau is truly driven by energy injection, the average X-ray and optical luminosities during the plateau phase, $L_{\rm X, plat, ave}$ and $L_{\rm opt, plat, ave}$, should naturally be correlated. Moreover, under this scenario, the scaling relations between the luminosities during the plateau and the normal decay phase are expected to be consistent since they share the same origin, i.e., synchrotron radiation from the external forward shock. Therefore, simultaneous multi-band observations are essential to verify this mechanism. In this work, we select a sample of 47 GRBs with simultaneous plateaus in both bands. We calculate their time-averaged isotropic luminosities for the plateau and the subsequent normal decay phases. We find a moderate positive correlation $\log L_{\rm X, plat, ave}=m\log L_{\rm opt, plat, ave}+c$ with a slope $m = 0.86 \pm 0.11$ for the plateau phase. This correlation supports the energy injection origin and offers a promising diagnostic approach to test the model. Furthermore, we obtain a similar slope $m = 1.05 \pm 0.05$ for the normal decay phase, which reinforces the idea that both phases share the same physical origin. Notably, the post-plateau data exhibit a systematic downward shift in luminosity, which may indicate the cessation of the central engine.

astro-ph.HE↗

arXiv2026

Impact of Neutrino Flavour Conversion on the Diffuse Neutrino Background from Neutrino-dominated Accretion Flows

Neutrino-dominated accretion flows (NDAFs) are believed to form during the fallback accretion phase of some core-collapse supernovae (CCSNe). Such systems produce copious neutrino emission, whose cumulative contribution over cosmic history forms the diffuse NDAF neutrino background (DNNB). As neutrinos propagate from the source to Earth, flavour conversion can significantly modify the observed neutrino spectra and consequently the detectability of the DNNB. In this work, based on fallback CCSN simulations, we investigate the effects of progenitor mass, metallicity, and initial explosion energy on neutrino emission from NDAFs. We calculate the heavy-lepton neutrino ($\nu_x$) spectra from NDAFs and incorporate them into DNNB predictions. We find that the unoscillated $\nu_x$ spectra are more than an order of magnitude lower than those of electron antineutrinos $\bar{\nu}_e$. Using the latest neutrino oscillation parameters reported by the Jiangmen Underground Neutrino Observatory (JUNO), we evaluate the impact of flavour conversion on the DNNB and derive the corresponding spectra for both the normal and inverted mass orderings. We further estimate the expected event numbers in JUNO and Hyper-Kamiokande. We find that the predicted DNNB signal is strongly dependent on the neutrino mass ordering. While the DNNB may be detectable in the normal ordering with next-generation neutrino detectors, the signal is significantly suppressed in the inverted ordering, making detection considerably more challenging.

astro-ph.HE↗

arXiv2026

Impact of disk magnetic fields on the propagation of stellar-scale jets in the magnetically arrested accretion disks of active galactic nuclei

It is widely recognized that active galactic nucleus (AGN) disks host numerous massive stars and compact objects. Stellar-scale jets triggered by collapses of massive stars and mergers of compact objects could propagate through the disk and produce observable electromagnetic radiation. Magnetically arrested disks (MADs), supported by both numerical simulations and observations, possess strong magnetic fields (MFs). As jets travel within such environments, the MFs should regulate jet evolution and shape radiation signatures. In this work, we explore the effects of disk MFs on jet propagation and breakout emission within the MAD framework. We employ a jet-cocoon model that accounts for potential disk-MF effects, including both magnetic pressure and magnetic energy dissipation driven by magnetic reconnection. We find that magnetic pressure effectively suppresses the lateral expansion of the cocoon, which enhances jet collimation and modestly increases the jet-head velocity. Furthermore, magnetic pressure effects are more pronounced at relatively low jet powers. In this regime, the breakout luminosity of the jet-head shock is enhanced, while its breakout time is shortened. However, the magnitude of the luminosity enhancement is sensitive to the adopted regime-dependent emission prescriptions. These findings suggest that, within the explored parameter space, disk MFs can facilitate the breakout of low-power jets arising from binary black hole mergers in AGN MADs.

astro-ph.HE↗

arXiv2026

A Parameter-Specific Retrieval and Knowledge-Guided Reasoning Framework for LLM-Based GPSR Optimization in FANETs

Existing Greedy Perimeter Stateless Routing (GPSR)-based protocols for Flying Ad-Hoc Networks (FANETs) struggle to adapt routing parameters, such as hello interval, multi-path number, and greedy forwarding weights, under highly dynamic environments. As an emerging artificial intelligence technology, large language models (LLMs) show potential for intelligent decision-making, providing new opportunities for adaptive adjustment of GPSR parameters to improve network performance. However, applying LLMs to GPSR remains challenging due to irrelevant experience retrieval and the absence of protocol constraints. To address these issues, we propose a Parameter-Specific Multi-Index Retrieval and Knowledge-Guided Reasoning framework for adaptive GPSR optimization (PMKR-GPSR), an LLM-based framework that enables protocol-consistent routing parameter adaptation. We design a parameter-specific multi-index retrieval mechanism to provide LLMs with parameter-relevant experiences while reducing interference from irrelevant information. We further construct a knowledge-guided constraint graph to enforce that the routing parameters satisfy dependency rules and optimization constraints. Simulation results demonstrate that PMKR-GPSR achieves higher packet delivery ratio and lower end-to-end delay under high-mobility FANETs.

cs.NI↗

arXiv2026

Capacity Markets for Large Loads under Supply-Chain Constraints

Motivated by the rapid growth of data centers, we develop a model to evaluate bringyour-own-capacity (BYOC) mandates and flexibility accreditation in capacity markets for new large loads with shared supply-chain constraints. With efficient pricing, BYOC mainly reallocates procurement between grid-built and self-built capacity and therefore has little welfare effect, while flexibility delivers a modest gain by reducing the effective capacity requirement. Under administrative price caps, mandates can improve static welfare by forcing data centers to internalize the full cost of capacity. The welfare ranking of the two instruments depends on supply-chain stress. At low or moderate stress, only the flexibility instrument raises welfare. Under severe stress with capped prices, the welfare gain from the BYOC obligation can exceed the gross flexibility benefit. The two instruments differ in their effects on a neighboring market: a unilateral BYOC mandate can crowd out its capacity investment, while flexibility produces essentially no spillover at our calibrated benchmark. Finally, applying current capacity non-performance penalties to flexible loads may lead to financial incentives that are too weak to induce truthful flexibility reporting.

eess.SY↗

arXiv2026

Emergent Replica Clock Unifies Many-Body Localization and Thermalization

Many-body localization (MBL) and eigenstate thermalization (ETH) are traditionally distinguished by a collection of separate diagnostics, not by a single order parameter. We show that replication and folding of isolated unitary dynamics generate a complex statistical mechanics of forward--backward history pairings and, in a closed cyclic infrared sector, an emergent clock $r_x\in\mathbb Z_t$. Its correlator has three distinct asymptotics: exponential decay in MBL, scale-free decay at criticality, and long-range locking in the thermal phase. A controlled $l$-bit reduction makes the clock action quasi-local, while its inverse correlation length obeys $\xi_{\rm pair}^{-1}=\kappa_{\rm el}=\ln|\rho_0/\rho_q|$, unifying history coherence, the defect line tension, and the transfer spectrum. Replica order supplies a second, discrete coordinate---the first order at which a hidden dynamical invariant becomes visible---and can distinguish localized dynamics that share the same spatial correlation length.

cond-mat.dis-nn↗

arXiv2026

LocAnyMed: Vision-Language Grounding for Multimodal Medical Images

Medical visual grounding connects free-form clinical queries to spatial evidence in medical images and is an important component of interpretable medical artificial intelligence. However, general-purpose grounding models are predominantly trained on natural images, while existing medical localization resources remain fragmented across imaging modalities, datasets, and task formulations. To address this gap, we construct LocAnyMed-200K, a multimodal medical visual grounding dataset containing approximately 200K image-query-answer examples across computed tomography, optical medical imaging, ultrasound, and X-ray. We harmonize heterogeneous detection and localization resources into a unified free-form instruction format that supports one or multiple bounding boxes, point coordinates, and no-target outputs for negative queries. Full-parameter fine-tuning of LocateAnything-3B on LocAnyMed-200K improves F1@IoU 0.50 from 10.64 to 85.59 on a held-out evaluation split, demonstrating that large-scale domain-specific supervision can equip a general grounding model with effective medical localization capabilities. Beyond spatial coordinates, a clinically interpretable grounding system should also communicate the evidence supporting its prediction. We therefore derive LocAnyMed-CoT-20K, a rationale-augmented subset that connects anatomical context, visual observations, and spatial conclusions through structured reasoning and further improves cross-source generalization through fine-tuning. Together, these resources provide a unified foundation for studying both localization accuracy and rationale quality across heterogeneous medical imaging modalities. The code is publicly available at https://github.com/MiliLab/LocAnyMed.

cs.CV↗

arXiv2026

Reincarnations of massive stars in active galactic nucleus discs

The origin and evolution of massive stars in active galactic nucleus (AGN) discs remain uncertain. We develop a semi-analytical model that follows the evolution of an embedded core-collapse supernova (CCSN) remnant and the subsequent formation and growth of a compact gas cloud. In the dense disc environment, efficient radiative cooling can strongly compress or bypass the Sedov-Taylor stage and drive the remnant rapidly into radiative snowplow evolution. After the remnant loses its interior pressure support, partial backflow of cooled shell fragments and refilling gas may initialize a pressure-confined and tidally limited seed cloud. The cloud then grows through shear-limited Hill capture until the gravitational, tidal, shear, photoionization, and magnetic conditions for collapse are simultaneously satisfied. The outcome depends strongly on the supermassive black-hole (SMBH) mass and explosion radius. Models with the lowest SMBH mass yield fewer than one massive star per event on average, whereas the most massive SMBH models can produce from several to several hundred. For a top-heavy initial mass function, massive stars dominate the resulting stellar mass and feedback budget. Embedded supernovae may therefore provide a localized gas-recycling channel for second-generation massive-star formation in AGN discs.

astro-ph.GA↗

arXiv2026

Distinct reentrant transitions in a quasi-periodic Raman lattice

We investigate a one-dimensional lattice with spin-orbit coupling (SOC) and a Zeeman potential containing uniform and quasiperiodic components. By tuning SOC, anomalous mobility edges emerge that separate critical from non-critical states, yielding a reentrant transition between two mixed phases, M$_1$$\to$M$_2$$\to$M$_1$, where M$_1$ (M$_2$) lacks (hosts) anomalous mobility edges. A new \emph{reentrant criticality transition}, defined as multiple entries into the critical phase, is identified. As a counterpart to reentrant delocalization/localization transitions, it completes the basic framework of reentrant phenomena across extended, localized, and critical states. The uniform Zeeman potential drives a reentrant delocalization transition, arising from the splitting of the localized region induced by the shift of mobility edges. This reveals a distinct pathway for reentrant phenomena beyond hybridization mechanisms.

cond-mat.dis-nn↗

arXiv2026

Optical Appearances of Accreting Ellis-Bronnikov Wormholes Observed from Both Sides of Throats

This study investigates the optical appearance of the Ellis-Bronnikov wormhole as viewed from both sides of its throat, under conditions of optically thick and thin accretion. By solving the geodesic equation, we derive the relationship between the impact parameter and the aiming distance of photons, and found that if the observer and the accretion disk are located on both sides of the throat, these two quantities are not equal. The optical image of the wormhole observed from the other side of the throat is obtained through the ray-tracing method. For optically thick accretion, increases in the parameter $n$ lead to an increase in the apparent size of the wormhole but a decrease in its brightness. For optically thin accretion, the image is similar to the internal and external inversion of the image observed from the other side. Furthermore, for optically thin accretion flows, the direct image does not block the emission from higher-order images, allowing radiation emitted from regions much closer to the event horizon to reach the observer. Our simulation results show that when the observer is on the $\mathcal{R}^+$ side, EB wormholes with small $n$ can mimic the images taken by the EHT to some extent, while wormholes with large $n$ or with the observer on the $\mathcal{R}^-$ side can be ruled out.

gr-qc↗