arXiv subjects

Yao Dong

Publications and source records attributed to Yao Dong.

At least 19 recordsLinked to original sources

arXiv2026

Nonreciprocal phonon blockade in spin quadratic optomechanical systems

We propose a scheme for achieving nonreciprocal phonon blockade in a quadratic optomechanical (QOM) system consisting of two spinning resonators near-field coupled to a nanomechanical oscillator. Due to the Sagnac-Fizeau effect, pump fields propagating in opposite directions experience distinct effective detunings,thereby leading to asymmetric intracavity intensities. Through the optical spring effect, this intensity imbalance gives rise to direction-dependent shifts in the effective mechanical frequency, providing the core mechanism for nonreciprocal phonon blockade. By judiciously setting parameters, single-phonon resonant excitation leads to conventional phonon blockade for one pump direction, whereas two-phonon resonance facilitates phononinduced tunneling (PIT) for the other. The pronounced nonreciprocity is quantified by a contrast ratio in the phonon second-order correlation function exceeding 55 dB. To elucidate the nonreciprocal statistics, the phonon blockade is further analyzed in terms of interference between the coherent component and squeezed fluctuations. Incorporating thermal phonons, we reveal an extended nonreciprocal thermal effect, where increasing thermal noise degrades antibunching toward Poissonian statistics in one direction, yet reverses the statistics from bunching to antibunching in the opposite direction. Our work provides a pathway toward nonreciprocal phonon devices and directional phonon switches, with potential applications in chiral networks and phononic information processing.

quant-ph↗

arXiv2026

FRFDet: Efficient UAV Small Object Detection with Symmetric Sampling and Scalable Fusion

Small object detection in Unmanned Aerial Vehicle (UAV) imagery remains challenging under adverse conditions, including complex weather, low illumination, and sensor noise. These challenges mainly stem from severe background clutter, fine-grained detail degradation, and suboptimal semantic-spatial feature fusion, which jointly hinder robust small-object representation. To this end, we propose FRFDet, a lightweight yet effective single-stage detector tailored for UAV-based small object detection. FRFDet proposes two plug-and-play modules: Inverse Bidirectional Sampling (IBS) and Scale-Feature Relationship Cross-Fusion (SFRCF). IBS preserves critical spatial details via channel expansion-compression and bidirectional pattern reconstruction, improving feature alignment. SFRCF explicitly models scale-dependent fusion behaviors, revealing that inter-group element-wise multiplication favors compact models, while inter-group additive fusion benefits larger architectures. Extensive experiments on VisDrone, UAVDT, HazyDet, and MS COCO demonstrate that FRFDet achieves state-of-the-art performance among lightweight detectors with low computational cost, compact parameters, and fast inference, making it well suited for resource-constrained UAV platforms.

cs.CV↗

arXiv2026

S1-DeepResearch: Beyond Search, Toward Real-World Long-Horizon Research Agents

Deep research agents aim to solve complex knowledge-intensive tasks through long-horizon planning, evidence gathering, reasoning, and report generation. While recent progress in search agents has demonstrated strong capabilities in information retrieval and answer verification, most existing training datasets remain search-centric, focusing primarily on closed-ended question answering and information localization. As a result, they mainly train information-seeking behavior while providing limited coverage of key deep research capabilities, including evidence integration, knowledge synthesis, planning, file understanding, and structured report generation. In this work, we propose a unified trajectory construction paradigm for deep research agents that combines closed-ended QA and open-ended exploration. The proposed framework consists of graph-grounded task formulation, agentic trajectory rollout, and multi-dimensional trajectory verification, enabling scalable synthesis of high-quality agentic trajectories spanning long-chain complex reasoning, deep research instruction following, report writing, file understanding and generation, and skills usage. Compared with existing search-oriented datasets, our synthesized trajectories place greater emphasis on knowledge synthesis, complex reasoning, and planning. S1-DeepResearch-32B achieves state-of-the-art performance among open-source models of comparable scale across 20 benchmarks spanning five capability dimensions, including complex reasoning, instruction following, report generation, file understanding, and skills usage. On several challenging deep research benchmarks, it approaches the performance of leading proprietary frontier models. These results highlight the importance of jointly modeling information acquisition, knowledge synthesis, and planning-oriented agent behaviors for building effective deep research agents.

cs.AI↗

arXiv2026

A Refinement of the Fixed--Pixed Points Equidistribution on restricted Permutations

Motivated by a recent conjecture of Bsila, Cox, Hugo, Styron and Zhuang concerning fixed points and pixed points on pattern-avoiding permutations, we prove a bivariate refinement involving descent statistics. Given a set of permutations $\Pi$, let $\mathfrak{S}_n(\Pi)$ denote the set of permutations in the symmetric group $\mathfrak{S}_n$ that avoid every element of $\Pi$ in the sense of pattern avoidance. For each set $\Pi$ appearing in their conjecture, we show that the pairs of statistics $(\mathrm{des},\mathrm{fix})$ and $(\mathrm{ides},\mathrm{pix})$ are equidistributed over $\mathfrak{S}_n(\Pi)$. Our proof is based on explicit ordinary generating functions for the corresponding pattern-avoiding classes.

math.CO↗

arXiv2026

Closeby Habitable Exoplanet Survey (CHES). V. Planetary Parameters Derived from Angular Separation Variations

The Closeby Habitable Exoplanet Survey (CHES) aims to achieve microarcsecond-level astrometry of about one hundred nearby FGK-type stars within 10 parsecs to detect Earth-like planets. Such precision exceeds the capability of absolute astrometry relying on Gaia catalogs, whose positional accuracy degrades over time due to error propagation from stellar motion and epoch offsets, limiting their use in microarcsecond-level detection. Traditional relative astrometry depends on positional components along right ascension and declination, requiring precise knowledge of field rotation and satellite attitude, which introduces additional errors. To address this, we propose a new relative measurement model based solely on variations in the length of angular separation between the target and reference stars, independent of direction. The model incorporates effects such as proper motion, parallax, radial velocity, light aberration, gravitational lensing, and planetary perturbations, enabling reconstruction of planetary orbits and masses. This approach enhances measurement stability and precision, providing a framework that is not entirely dependent on the Gaia catalog and suitable for CHES and other future high-accuracy astrometric missions.

astro-ph.EP↗

arXiv2026

Nonreciprocity of intense light field and weak quantum signal in optomechanical systems with three-mode parametric interactions

We demonstrate nonreciprocal optical transmission for both intense classical fields and weak quantum signals within a reconfigurable optomechanical platform driven by three-mode parametric interactions. The platform is modular, where each three-mode optomechanical system serves as a fundamental building block. Operating independently, a single block achieves nonreciprocity for classical fields. Specifically, asymmetric radiation pressure from intrinsic optomechanical nonlinearity induces nonreciprocal mechanical displacement, modulating the cavity intensity through optomechanical feedback. This enables full isolation of backward transmission without requiring parameter initialization. Alternatively, for quantum signals, the platform is reconfigured by activating photonic and phononic exchange channels between the two blocks. In this configuration, nonreciprocity arises from quantum interference between direct photon hopping and indirect conversion pathways. Constructive interference enables unidirectional low-loss transmission, while destructive interference completely suppresses the reverse direction. After adiabatically eliminating the auxiliary modes, the optimal nonreciprocal frequency and the trade-off between insertion loss and nonreciprocal bandwidth can be controlled by engineering optomechanically induced mechanical dissipation. Additionally, the three-mode-based device requires less control-field power than two-mode systems under resolved-sideband conditions, demonstrating versatile potential for optical nonreciprocity applications across classical and quantum domains.

quant-ph↗

arXiv2025

The Formation of Ultra-short-period Planets under the Influence of the Nearby Planetary Companions

Ultra-short-period (USP) planets, defined as those with orbital periods shorter than 1 day, provide valuable insights into planetary evolution under strong stellar tidal interactions. In this work, we investigate the formation of USP planets in two-planet systems consisting of an inner terrestrial planet accompanied by an outer hot Jupiter (HJ). Our simulation results show USP planets can form through a process driven by secular perturbations from the outer companion, which induce eccentricity excitation, tidal dissipation, and subsequent orbital decay of the inner planet. The probability of USP formation is governed by key factors, including the mass ratio between two planets, their orbital eccentricities, and the tidal dissipation process. 6.7\% of our simulations form USP planets, and USP planets form most efficiently when the mass ratio is around 4 $M_{\oplus}{\rm /}M_{\rm J}$, with the inner planet less than 8 $M_{\oplus}$. Furthermore, the eccentricity of the outer HJ plays a crucial role-moderate eccentricities ($e_{\rm outer}<0.1$) favor USP formation, whereas higher eccentricities ($e_{\rm outer}>0.1$) enhance the likelihood of orbital instability, often resulting in a lonely HJ. USP planets form more efficiently when the tidal dissipation function of the inner planet is comparable to the values estimated for terrestrial planets in the solar system. Comparison with observed planetary systems reveals that systems with large mass ratios or nearly circular outer planets tend to produce short-period (SP) planets instead of USP planets. Our findings offer a potential explanation for the most commonly observed system architectures, which predominantly feature either an HJ with an inner SP planet or a lonely HJ.

astro-ph.EP↗

arXiv2025

Direct Imaging for the Debris Disk around $\epsilon$ Eridani with the Cool-Planet Imaging Coronagraph

We analyze the inner debris disk around $\epsilon$ Eridani using simulated observations with the Cool-Planet Imaging Coronagraph (CPI-C). Using the radiative transfer code MCFOST, we generate synthetic scattered-light images and spectral energy distributions for three disk models that differ in inclination and radial extent, and compare these results with the anticipated performance of CPI-C. CPI-C can resolve disk structures down to $\sim$3 au, offering substantially finer spatial resolution than existing HST/STIS and Spitzer/IRS observations. Recovered inclinations and radial extents closely match the input models, constraining the disk geometry and informing potential planet-disk interactions in the $\epsilon$ Eri system. Although the cold Jupiter-like planet $\epsilon$ Eri b is not detected in our simulations, polarimetric methods may enable detection of its reflected light. These results highlight the capability of next-generation coronagraphs to probe cold dust in nearby planetary systems.

astro-ph.EP↗

arXiv2025

Unconventional photon blockade in a hybrid optomechanical system with an embedded spin-triplet

The research article studies the unconventional photon blockade effect in a hybrid optomechanical system with an embedded spin-triplet state. The interaction between the optomechanical system and the spin state generates new transition paths for the destructive quantum interference of the two-photon excitation state. By analytically solving the Schrodinger equation and numerically simulating the master equation, it can be found that the modulated mechanical dissipation is essential for achieving the strong photon blockade in our system. Unlike the conventional cavity optomechanical system, the second-order correlation function g(2)(0) =0 can be obtained with the weak single-photon optomechanical coupling. By adjusting the system parameters, the strong photon blockade and the single-photon resonance can coincide, which indicates the hybrid system has the potential to be a high-quality and efficient single-photon source. Finally, the influence of the thermal noise on photon blockade is investigated. The results show that the second-order correlation function is more robust for the weaker phonon-spin coupling.

quant-ph↗

arXiv2025

Closeby Habitable Exoplanet Survey (CHES). IV. Synergy between astrometry and direct imaging missions of the Habitable World Observatory for detecting Earth-like planets

The detection and characterization of habitable planets around nearby stars persist as one of the foremost objectives in contemporary astrophysics. This work investigates the synergistic integration of astrometric and direct imaging techniques by capitalizing on the complementary capabilities of the Closeby Habitable Exoplanet Survey (CHES) and Habitable Worlds Observatory (HWO). Planetary brightness and position vary over time due to phase effects and orbital architectures, information that can be precisely provided by CHES's astrometric measurements. By combining the precise orbital constraints from CHES with the imaging capabilities of HWO, we evaluate the improvements in detection efficiency, signal-to-noise ratio and overall planet yield. Completeness is quantified as the fraction of injected planets that are successfully detected, while yields are estimated for various scenarios using terrestrial planet occurrence rates derived from the Kepler dataset. Our results indicate that prior astrometric data significantly enhance detection efficiency. Under the adopted detection limit, our analysis indicates that prior CHES observations can increase completeness by approximately 10% and improve detection efficiency by factors ranging from two to thirty. The findings underscore the importance of interdisciplinary approaches in the search for and characterization of habitable worlds.

astro-ph.EP↗

arXiv2025

Closeby Habitable Exoplanet Survey (CHES). III. Retrieval of Planetary Masses in Binaries Using the N-body Model with RV and Astrometry Synergy

Given that secular perturbations in a binary system not only excite high orbital eccentricities but also alter the planetary orbital inclination, the classical Keplerian orbital model is no longer applicable for orbital retrieval. The combination of a dynamical model and observational data is essential for characterizing the configuration and planetary mass in close binaries. We calculate the theoretical radial velocity (RV) signal in the N-body framework and observe a drift in the RV semi-amplitude, which leads to a reduction in the $m$sin$i$ detection threshold by 20 $M_{\oplus}$, with $\sim$ 100% detection probability in the $m_1$sin$i_1$-$a_1$ parameter space. High-precision RV data with an accuracy of 1 m/s can detect such dynamical effects. For four close-in binaries-GJ 86, GJ 3021, HD 196885, and HD 41004, the deviation between the minimum mass derived from the Keplerian and N-body models is found to be $> 0.2 ~ M_{\mathrm{Jup}}$. High-precision astrometric data are also necessary to resolve the 3D orbits and true masses exoplanets. We generate astrometric simulation data with accuracies corresponding to Gaia (57.8 $\mu$as) and the Closeby Habitable Exoplanet Survey (CHES) (1 $\mu$as), respectively. Joint orbit fitting is performed for RV + Gaia and RV + CHES synergy methods. Compared with the fitting results from the astrometry-only model, the synergy models more effectively constrain the range of orbital inclinations. Using simulation data, we derive precise uncertainties for the true planetary mass, which are critical for determining the evolution of planets around binary stars and multi-planet systems.

astro-ph.EP↗

arXiv2025

Formation of Ultra-short-period Planet in Hot Jupiter Systems: Application to WASP-47

The WASP-47 system is notable as the first known system hosting both inner and outer low-mass planetary companions around a hot Jupiter, with an ultra-short-period (USP) planet as the innermost planetary companion. The formation of such an unique configuration poses challenges to the lonely hot Jupiter formation model. Hot Jupiters in multiple planetary systems may have a similar formation process with warm Jupiter systems, which are more commonly found with companions. This implies that the WASP-47 system could bridge our understanding of both hot and warm Jupiter formation. In this work, we propose a possible formation scenario for the WASP-47 system based on its orbital configuration. The mean motion resonance trapping, giant planet perturbations, and tidal effects caused by the central star are key factors in the formation of USP planets in multiple planetary systems with hot Jupiters. Whether a planet can become an USP planet or a short period super-earth (SPSE) planet depends on the competition between eccentricity excitation by nearby giant planet perturbations and the eccentricity damping due to tidal effects. The $Q_p'$ value of the innermost planet is essential for the final planetary configuration. Our results suggest that a $Q_p'$ in the range of [1, 10] is favorable for the formation of the WASP-47 system. Based on the formation scenario, we estimate an occurrence rate of 8.4$\pm$2.4\% for USP planets in systems similar to WASP-47.

astro-ph.EP↗

arXiv2025

Web permutations, Seidel triangle and normalized $γ$-coefficients

The web permutations were introduced by Hwang, Jang and Oh to interpret the entries of the transition matrix between the Specht and $\mathrm{SL}_2$-web bases of the irreducible $§_{2n}$-representation indexed by $(n,n)$. They conjectured that certain classes of web permutations are enumerated by the Seidel triangle. Using generating functions, Xu and Zeng showed that enumerating web permutations by the number of drops, fixed points and cycles gives rise to the normalized $γ$-coefficients of the $(α,t)$-Eulerian polynomials. They posed the problems to prove their result combinatorially and to find an interpretation of the normalized $γ$-coefficients in terms of cycle-up-down permutations. In this work, we prove the enumerative conjecture of Hwang-Jang-Oh and answer the two open problems proposed by Xu and Zeng.

math.CO↗

arXiv2024

SCSA: Exploring the Synergistic Effects Between Spatial and Channel Attention

Channel and spatial attentions have respectively brought significant improvements in extracting feature dependencies and spatial structure relations for various downstream vision tasks. While their combination is more beneficial for leveraging their individual strengths, the synergy between channel and spatial attentions has not been fully explored, lacking in fully harness the synergistic potential of multi-semantic information for feature guidance and mitigation of semantic disparities. Our study attempts to reveal the synergistic relationship between spatial and channel attention at multiple semantic levels, proposing a novel Spatial and Channel Synergistic Attention module (SCSA). Our SCSA consists of two parts: the Shareable Multi-Semantic Spatial Attention (SMSA) and the Progressive Channel-wise Self-Attention (PCSA). SMSA integrates multi-semantic information and utilizes a progressive compression strategy to inject discriminative spatial priors into PCSA's channel self-attention, effectively guiding channel recalibration. Additionally, the robust feature interactions based on the self-attention mechanism in PCSA further mitigate the disparities in multi-semantic information among different sub-features within SMSA. We conduct extensive experiments on seven benchmark datasets, including classification on ImageNet-1K, object detection on MSCOCO 2017, segmentation on ADE20K, and four other complex scene detection datasets. Our results demonstrate that our proposed SCSA not only surpasses the current state-of-the-art attention but also exhibits enhanced generalization capabilities across various task scenarios. The code and models are available at: https://github.com/HZAI-ZJNU/SCSA.

cs.CV↗

arXiv2024

Rational Sensibility: LLM Enhanced Empathetic Response Generation Guided by Self-presentation Theory

The development of Large Language Models (LLMs) provides human-centered Artificial General Intelligence (AGI) with a glimmer of hope. Empathy serves as a key emotional attribute of humanity, playing an irreplaceable role in human-centered AGI. Despite numerous researches aim to improve the cognitive empathy of models by incorporating external knowledge, there has been limited attention on the sensibility and rationality of the conversation itself, which are vital components of the empathy. However, the rationality information within the conversation is restricted, and previous methods of extending knowledge are subject to semantic conflict and single-role view. In this paper, we design an innovative encoder module inspired by self-presentation theory in sociology, which specifically processes sensibility and rationality sentences in dialogues. And we employ a LLM as a rational brain to decipher profound logical information preserved within the conversation, which assists our model in assessing the balance between sensibility and rationality to produce high-quality empathetic response. Experimental results demonstrate that our model outperforms other methods in both automatic and human evaluations.

cs.AI↗

arXiv2024

Closeby Habitable Exoplanet Survey (CHES). II. An Observation Strategy for the Target Stars

The Closeby Habitable Exoplanet Survey (CHES) constitutes a mission intricately designed to systematically survey approximately 100 solar-type stars located within the immediate proximity of the solar system, specifically within a range of 10 parsecs. The core objective of this mission is the detection and characterization of potentially habitable Earth-like planets or super-Earths within the habitable zone of these stars. The CHES mission obtains high-precision astrometric measurements of planets orbiting the target stars by observing angular distance variations between the target star and reference stars. As a result, we surveyed the relevant parameters of both target and reference stars in detail, conducting a thorough analysis and calculation of the required observation accuracy, the number of observations, and the priority assigned to each target star. Observational emphasis will be concentrated on targets considered of higher priority, ensuring the effectiveness of their observation capabilities. Through this approach, we formulate a five-year observation strategy that will cover all the target stars within a six-month timeframe. The strategy not only fulfills the required observing capability but also exhibit high efficiency simultaneously, providing an executable program for future mission. Over the span of the mission's five-year duration, a cumulative observation time of 29,220 hours will be available. Approximately 86 percent of this, totaling 25,120 hours, is allocated for the observation of target stars. This allocation leaves approximately 4,100 hours for extended scientific observation programs. We have also performed simulated observations based on this strategy and verified its observational capability for exoplanets.

astro-ph.EP↗

arXiv2024

Closeby Habitable Exoplanet Survey (CHES). I. Astrometric Noise and Planetary Detection Efficiency due to Stellar Spots and Faculae

The Closeby Habitable Exoplanet Survey (CHES) is dedicated to the astrometric exploration for habitable-zone Earth-like planets orbiting solar-type stars in close proximity, achieving unprecedented micro-arcsecond precision. Given the elevated precision, thorough consideration of photocenter jitters induced by stellar activity becomes imperative. This study endeavors to model the stellar activity of solar-type stars, compute astrometric noise, and delineate the detection limits of habitable planets within the astrometric domain. Simulations were conducted for identified primary targets of CHES, involving the generation of simulated observed data for astrometry and photometry, accounting for the impact of stellar activity. Estimation of activity levels in our samples was achieved through chromospheric activity indices, revealing that over 90% of stars exhibited photocenter jitters below 1 $μ\mathrm{as}$. Notably, certain proximate stars, such as $α$ Cen A and B, displayed more discernible noise arising from stellar activity. Subsequent tests were performed to evaluate detection performance, unveiling that stellar activity tends to have a less pronounced impact on planetary detectability for the majority of stars. Approximately 95% of targets demonstrated a detection efficiency exceeding 80%. However, for several cold stars, e.g., HD 32450 and HD 21531, with the habitable zones close to the stars, a reduction in detection efficiency was observed. These findings offer invaluable insights into the intricate interplay between stellar activity and astrometric precision, significantly advancing our understanding in the search for habitable planets.

astro-ph.EP↗

arXiv2024

A $q$-analog of the Stirling-Eulerian Polynomials

In 1974, Carlitz and Scoville introduced the Stirling-Eulerian polynomial $A_n(x,y|α,β)$ as the enumerator of permutations by descents, ascents, left-to-right maxima and right-to-left maxima. Recently, Ji considered a refinement of $A_n(x,y|α,β)$, denoted $P_n(u_1,u_2,u_3,u_4|α,β)$, which is the enumerator of permutations by valleys, peaks, double ascents, double descents, left-to-right maxima and right-to-left maxima. Using Chen's context-free grammar calculus, Ji proved a formula for the generating function of $P_n(u_1,u_2,u_3,u_4|α,β)$, generalizing the work of Carlitz and Scoville. Ji's formula has many nice consequences, one of which is an intriguing $γ$-positivity expansion for $A_n(x,y|α,β)$. In this paper, we prove a $q$-analog of Ji's formula by using Gessel's $q$-compositional formula and provide a combinatorial approach to her $γ$-positivity expansion of $A_n(x,y|α,β)$.

math.CO↗