NeurIPS 2026 论文列表

Recent advances in online learning have achieved an $O(n/\Delta_{[2]})$ query complexity in quantum $n$-arm multi-armed bandits (MABs) for best-arm identification, which represents a quadratic speedup over their classical counterparts. Here and throughout, $\Delta_{[2]}$ is the gap between the mean of the best and second-best arms. However, the implementations of these algorithms remain on a small scale due to various aspects of quantum hardware restrictions. One of the most significant restrictions is \emph{memory decoherence}, in which the qubits quickly lose information after a short period of time. Memory decoherence can occur at \emph{intra-circuit} and \emph{inter-circuit} levels. Intra-circuit decoherence happens often in near-term quantum computers, where the noise becomes overwhelming when the circuit is deep. On the other hand, inter-circuit decoherence captures future quantum machines, where a quantum memory is promising, but objects stored in the memory for too long can still become decoherent. In this paper, we present a comprehensive treatment of both memory decoherence problems. For inter-circuit decoherence, we derive a framework based on streaming bandits, and we obtain an algorithm that finds the best arm with high constant probability using $O(n/\Delta_{[2]})$ queries and an $O(\log{n})$ decoherence window. This is the first quantum algorithm for MABs that achieves an $o(n)$ decoherence window, which represents an exponential improvement. For intra-circuit decoherence, we observe that only $O(1)$-depth circuits can be used to avoid significant decoherence. Therefore, we devise various hardware optimizations and a destructive SWAP test subroutine to speed up the empirical performance. On the IBM Q System One machine with 127 qubits, our implementation scales the quantum MABs to over $1000$ arms, and our algorithms consistently achieve significant efficiency improvements over classical bandit algorithms in both physical experiments and computer simulations.

The Quality-Diversity (QD) optimization aims to discover a collection of high-performing solutions that simultaneously exhibit diverse behaviors within a user-defined behavior space. This paradigm has stimulated significant research interest and demonstrated practical utility in domains including robot control, creative design, and adversarial sample generation. A variety of QD algorithms with distinct design principles have been proposed in recent years. Instead of proposing a new QD algorithm, this work introduces a novel reformulation by casting the QD optimization as a multi-objective optimization (MOO) problem with a huge number of optimization objectives. By establishing this connection, we enable the direct adoption of well-established MOO methods, particularly set-based scalarization techniques, to solve QD problems through a collaborative search process. We further provide a theoretical analysis demonstrating that our approach inherits theoretical guarantees from MOO while providing desirable properties for the QD optimization. Experimental studies across several QD applications confirm that our method achieves performance competitive with state-of-the-art QD algorithms.

Quantitative analysis of animal behavior in neuroscience increasingly relies on accurate 3D pose, yet current large-scale mouse datasets are restricted to top-down views and suffer from occlusion and keypoint ambiguity. We introduce QDMouse4M, a six-view dataset of freely moving mice with physically grounded 2D and 3D keypoint annotations obtained from subdermal quantum-dot fluorescence markers. QDMouse4M contains over four million reflectance frames with matched fluorescence frames, 2D and 3D pose trajectories and behavior classifications. We use the dataset to evaluate markerless 2D and 3D pose estimation with SLEAP and Lightning Pose 3D across training-set sizes, backbones, and in-session/out-of-session splits. We further show that the released trajectories support downstream spontaneous-behavior analysis with Keypoint-MoSeq and stride-level gait measurements. QDMouse4M provides a benchmark-scale, physically grounded resource for developing and evaluating pose estimation, behavior understanding, and biomechanics models under realistic dark-environment laboratory conditions.

Multi-agent systems (MASs) are increasingly deployed for complex tasks, yet their security against indirect prompt injection remains poorly understood. As frontier LLMs become more robust to injections with overtly malicious semantics, such as credential exfiltration, unauthorized transactions, or policy bypass, the residual attack surface shifts to task hijacking: an injection that silently redirects an MAS toward an attacker-chosen alternative task plausibly within the agent's domain, such as the wrong patient's record, a competitor's product, or a different CVE. There is no malicious verb to refuse, and existing benchmarks, designed around overtly malicious goals in single-agent settings, do not characterize this surface. We introduce PurpleAudit, an auditing framework that lets a practitioner stress-test their own MAS against task hijacking and derive a tailored system-prompt defense. The framework couples 22 baseline attacks and four prompt/tool-level defense baselines from the literature with a co-evolutionary purple-team procedure, in which red- and blue-team agents evolve stronger attacks and adaptive defenses by reasoning over each other's execution traces. Applied across frontier backends on ten MASs and a real-world MAS with live web access, PurpleAudit surfaces an MAS-specific attack pattern that frames the injection as a prerequisite for completing the user's task, reaching 31.26% ASR on Claude Opus 4.5 under the framework's auditing protocol, where 22 baseline attacks fail entirely. The co-evolved defense suppresses both baseline and evolved attacks at negligible utility cost, transfers across reasoning-capable backends, and operates at the prompt level with low deployment overhead.

Motivated by applications in reinforcement learning from human feedback, we consider a setting where a given collection of rankings needs to be compressed into a smaller collection of rankings. This can also be seen as a combination of two fundamental social choice frameworks: ranking aggregation and multiwinner voting. We propose three proportionality notions that capture different types of representation in this setting: positional proportionality, pairwise proportionality, and proportionality for solid coalitions (PSC). On the one hand, we show that positional proportionality and PSC are always satisfiable for any input rankings and target compression size, and a desired output can be found in polynomial time. On the other hand, we prove that pairwise proportionality cannot be satisfied in general, but can nevertheless be attained when the input rankings are single-peaked or single-crossing.

Patient history taking is a strategic, multi-turn process that refines diagnostic hypotheses through iterative questioning, mirroring clinical reasoning where each inquiry updates beliefs over candidate diagnoses. Deploying AI in this setting is constrained by privacy, cost, and latency, making Small Language Models (SLMs) a more desirable backbone compared to larger LLMs. However, SLMs capture only the fast, intuitive "System 1" side of this process and lack explicit mechanisms for the deliberative "System 2'' reasoning needed to maintain and update diagnostic uncertainty over time. Bayesian Networks (BayesNets) offer a natural complement, providing an interpretable framework for auditable probabilistic belief tracking. Yet, clinical BayesNets are difficult to construct due to reliance on expert-curated structure, dependencies, and parameters. We introduce ProbMedTOD, that automatically synthesizes a clinical BayesNet from a small number of clinical notes in three stages: ontology building, structure prediction, and parameter estimation. ProbMedTOD then integrates the resulting BayesNet with SLMs enabling probabilistic reasoning in multi-turn dialogues. A BayesNet Agent maintains real-time posterior distributions over diagnoses, while a Policy Agent picks the diagnostically informative questions. Experiments on DDXPlus and MIMIC-IV Notes show that ProbMedTOD outperforms LLM-only and retrieval-based baselines, with especially strong gains for smaller models.

Tool-use benchmarks often score agents by final task success, but terminal outcomes can obscure whether the intermediate tool-call trajectory was executable. We propose prefix executability as a trajectory-level evaluation protocol for tool-using agents. The protocol measures whether every prefix of a predicted tool-call sequence remains executable under tool schemas, state preconditions, and data dependencies, and summarizes reliability using Prefix Executability Curves (PEC), First-Error Depth (FED), Trajectory Executability Rate (TER), horizon-normalized AUC-PEC, and Recovery Rate (RR). We instantiate the protocol on stratified samples from BFCL-v3 multi-turn and ToolSandbox. Across both benchmarks, outcome-only and prefix-level rankings diverge: agents whose execution is conditioned on an unverified plan often achieve higher point-estimate final success than non-plan-conditioned baselines while substantially lowering TER and AUC-PEC. These divergences are precisely the failure modes that prefix executability is designed to expose: they reveal whether apparent success rests on an executable trajectory, where invalidity first enters, and whether success follows recovery from an earlier failure. As a validation intervention, explicit pre-execution plan checking reverses much of this prefix-reliability loss, consistently improving executable-prefix survival while maintaining competitive terminal success. These results show that final success alone is insufficient for evaluating tool-use agents and that prefix-level executability provides an actionable reliability signal for comparing agents, diagnosing failures, and assessing validation mechanisms.

Multi-objective reinforcement learning (MORL) seeks to train agents capable of balancing conflicting objectives. While single preference-conditioned policies offer a highly scalable solution, existing approaches remain brittle in practice, frequently failing to recover dense Pareto fronts. We demonstrate that this failure stems from two structural pathologies: destructive advantage cancellation caused by premature Early Scalarization (ES), and representational mode collapse across the preference space. To overcome these bottlenecks, we introduce \toolname{}, a PPO-based framework that fundamentally reorganizes multi-objective optimization. By preserving per-objective learning signals through a decomposed pipeline and integrating preferences only after trust-region stabilization (Late-Stage Weighting), \toolname{} improves credit assignment under conflicting objectives. Concurrently, a scaled diversity regularizer encourages behavioral divergence proportional to preference distance. \toolname{} operates entirely within the efficient linear scalarization regime shared by standard deep MORL baselines. By reducing information loss caused due to linear scalarization rather than relying on expensive non-linear utility functions, it suggests that optimization bottlenecks play a significant role. Across available standard benchmarks, including high-dimensional and many-objective environments, \toolname{} consistently discovers broader, higher-quality Pareto fronts than prior methods, exceeding state-of-the-art hypervolume and expected utility using a single deployable policy.

The Abstraction and Reasoning Corpus (ARC) has become a prominent benchmark for evaluating skill acquisition in AI models. Yet standard ARC evaluation considers only a single capability: producing the correct output grid for a test input. We argue that this narrow format underestimates the diversity of abilities required for genuine abstract skill acquisition. We introduce PotARCin, a benchmark that extends ARC by assessing understanding of a task’s underlying abstract rule across five dimensions: Definition, Classification, Constrained Generation, Editing, and Inversion. PotARCin uses explicit generator and verifier programs, enabling dynamic generative sampling beyond fixed input-output pairs. Across four state-of-the-art models evaluated on the ARC-AGI-1 training set, we observe a 30–50 percentage-point performance gap between standard ARC evaluation and PotARCin. We further investigate effects of generative sampling, difficulty of corruption types and questions of self-consistency. We also introduce P-ARC, a hand-crafted test set with generator and verifier programs, on which models achieve 0-8% accuracy across all five dimensions, underscoring the difficulty of acquiring versatile abstract skills.

Lotteries and tickets are often used as a didactical analogy to explain the success of overparameterized neural networks: “larger networks succeed because they more likely contain a well-initialized subnetwork that can learn the task in isolation, much like buying more tickets increases the chances of winning a lottery.” This explanation is intuitive but misleading: it suggests that subnetworks can be treated in isolation from the rest of the network. Following this reasoning leads to interpreting learning in wide networks as a multi-start optimization process, where gradient descent simply conducts a parallel search over subnetworks. We argue that this view is flawed since, among other reasons, winning tickets can be made to fail by perturbing the rest of the network. We put forward a more accurate intuitive picture for the success of overparameterization based on the geometry of loss landscapes: increasing width expands the set of available dimensions for optimization, making it easier to escape bad local minima. Moreover, as width grows, bad minima become increasingly rare relative to good minima. As the field grows mature, it is important to refine the analogies we use to explain foundational phenomena, such as the apparent redundancy of large networks, reconciling practitioners' intuitions with modern theoretical insights.

When distinct pre-trained models are specialized for the same task, they often converge to nearly equivalent functional behaviors, while the underlying parameter-space changes share no common coordinate system. Existing approaches that compose such changes arithmetically are therefore confined to a single model, leaving task knowledge stranded inside the network that acquired it. Drawing on Plato's allegory of the cave, we hypothesize that these model-specific updates are shadows cast by a shared, model-agnostic object that governs how task specialization reshapes a model's behavior, and we refer to this object as the platonic task vector. To make this view operational, we introduce Universal Task Descriptors, matrices whose shape is fixed independently of architecture or embedding dimension and that capture a task's functional effect in a model-transferable form. Universal Task Descriptors admit addition, negation, and analogy in closed form, and a lightweight realization step then transfers any composed descriptor into a chosen target model. Experiments across a range of models and tasks indicate that this pipeline transfers and composes task knowledge across heterogeneous models.

We present an in-depth evaluation of LLMs' ability to negotiate, a central business task requiring strategic reasoning, theory of mind, and economic value creation. To do so, we introduce **PieArena**, a large-scale negotiation benchmark grounded in multi-agent interactions over realistic scenarios adapted from MBA negotiation courses at an elite business school. We evaluate language agents across three pairing regimes: mirror-play, cross-play, and human–LM play. We develop a ranking model for continuous negotiation payoffs that yields order-invariant, uncertainty-quantified leaderboards while correcting for systematic experimental asymmetries. We further study the effects of joint-intentionality agentic scaffolding and find asymmetric gains, with large improvements for mid- and lower-tier LMs and diminishing returns for frontier LMs. As calibration anchors, we collect human–human and human–LM negotiation data from trained business school students, finding that a representative frontier language agent (GPT-5) matches or exceeds this human baseline in our evaluation settings. Beyond deal outcomes, PieArena provides a multi-dimensional behavioral profile that reveals cross-model heterogeneity in instruction compliance, computation accuracy, as well as judge-assessed deception and reputation, illustrating the value of evaluation beyond outcome-only leaderboards.

Physical AI Smart Spaces is, to the best of our knowledge, the first benchmark to simultaneously provide large-scale, multi-class, and multi-camera 3D perception data for indoor smart spaces. It contains over 280 hours of synchronized 1080p footage captured by nearly 1,800 cameras in warehouses, hospitals, retail venues, and similar settings, together with automatic annotations for multi-camera identities, 2D bounding boxes, 3D bounding boxes, camera calibration, and depth where available. The benchmark spans Isaac Sim synthetic generation, Cosmos Transfer appearance augmentation, and real-world Sim2Real evaluation. For the real-world target, we include two warehouse deployments with time-synchronized streams, automatic VGGT-based calibration, and a 3D labeling interface that projects world-frame 3D boxes into each view for cross-camera verification. We describe the dataset scope, annotation and calibration schema, generation workflow, benchmark protocols, and official evaluation system, which standardizes submission format, and leaderboard reporting. A central contribution is a 3D instantiation of Higher Order Tracking Accuracy (HOTA), extending the usual 2D box-based tracking evaluation to 3D locations and 3D boxes. We further report empirical baselines from the AI City Challenge leaderboards, showing how methods evolve from person-only 3D location tracking to multi-class 3D box tracking under realistic smart-space constraints. The release is available at https://huggingface.co/datasets/nvidia/PhysicalAI-SmartSpaces.

Tensor Singular Value Decomposition (t-SVD) has achieved strong empirical performance in multi-view clustering (MVC) and its incomplete setting (IMVC). However, the success of this framework heavily relies on the implicit dependency of its Fourier transform on the sample sequence, which raises serious concerns regarding sample-permutation sensitivity. To address this issue, we first formulate the permutation sensitivity in multi-view clustering by providing rigorous definitions of invariance at both the outcome level and the representation level. Secondly, by revealing the potential structural risks associated with the fixed Fourier basis, we propose two plug-and-play strategies: (1) an Order-Restoration strategy (K-OR), designed to reconstruct a locally smooth signal favored by the Fourier transform; and (2) an equivariant t-SVD framework (Cor-SVD), which fundamentally resolves the sensitivity of the Fourier transform by replacing fixed bases with data-dependent, equivariant transforms. Finally, we design a controlled permutation evaluation protocol to verify the robustness of tensorial clustering models. Extensive experiments demonstrate the significant performance variability of existing t-SVD-based methods under sample permutations, whereas our approaches substantially improve their permutation robustness while maintaining competitive clustering performance. These findings reveal critical vulnerabilities in current tensorial clustering benchmarks and underscore the necessity of the proposed method for achieving robust performance and reliable evaluation.

We introduce Panoptic Saliency Ranking (PSR), a new task that aims to estimate the visual saliency of all objects within a scene. Unlike salient object ranking, which focuses only on ranking salient regions, PSR extends the problem to the entire scene, providing a holistic and fine-grained understanding of visual saliency. To facilitate this task, we construct PSR18K, the first large-scale benchmark for panoptic saliency ranking. It contains 17,861 images with 146,460 annotated object instances spanning 13 superclasses and 376 fine-grained categories. In addition, PSR18K provides relation graph annotations to explicitly model semantic and spatial relationships among objects. We further propose an efficient Intrinsic Relation Graph Network (IRGNet), which reinterprets Transformer self-attention as an implicit relational matrix and seamlessly transforms it into an explicit relation graph, thereby obviating the need for additional relation modeling and significantly improving inference speed. Extensive experiments on PSR18K and three widely used SOR benchmarks demonstrate that our IRGNet achieves new state-of-the-art performance and faster inference with fewer parameters. The dataset and code are publicly available at https://sites.google.com/view/PSR18K.

Preference ranking modeling is important for selecting and adapting language-model responses to human preferences. Compared with deterministic ranking methods, generative preference ranking models the prompt-response data distribution, providing richer uncertainty characterization and sample diversity for learning a more expressive ranking boundary. Recent work improves modeling efficiency by shifting generative preference ranking from textual space to embedding space, but without explicit preference-conditioned separation, the learned embedding distribution may still entangle preferred and rejected responses, producing ambiguous synthetic samples that weaken the ranking boundary. To address this issue, we propose PRISM, a Preference Ranking framework through dISentangled embedding Modeling. PRISM formulates embedding-level generative preference ranking with a unified class-conditional ELBO and decomposes this optimization objective to expose the encoded latent entanglement between preferred and rejected embeddings. This derivation motivates two practical preference-aware generation variants: PRISMMI, involving a deep class-separation objective, and PRISMMMD, catering a probabilistic aggregate-matching objective. Both variants learn a preference-disentangled embedding data distribution and synthesize data pairs that preserve ranking semantics for the generative ranking boundary. Experiments show that PRISM improves preference ranking performance and produces useful generated embeddings for downstream response selection. The anonymous code repository is available at:https://anonymous.4open.science/r/PRISM-915C/README.md.

Multi-output Gaussian process (MOGP) regression allows modelling dependencies among multiple correlated response variables. Similarly to standard Gaussian processes (GPs), MOGPs are sensitive to model misspecification and outliers, which can distort predictions within individual outputs. In the multi-output case, this situation can be further exacerbated as anomalous observations in one response can adversely influence predictions for other correlated outputs. To handle this situation, we propose R-MOGP—an MOGP that is provably robust to outliers in any individual response. Our approach preserves conjugacy, achieving robustness without sacrificing computational efficiency. Empirically, we show that R-MOGP achieves performance comparable to existing state-of-the-art robust MOGPs at a fraction of their computational costs.

Large Language Model-based Multi-Agent Systems (LLM-based MAS) have shown remarkable success in solving complex tasks by coordinating specialized agents through multi-step workflows. To overcome the high cost and specificity of manually designed workflows, recent research has shifted toward learning them automatically. However, a key limitation remains: while agent calls introduce significant latency due to model inference time and service congestion, most automated methods optimize solely for downstream performance, ignoring execution time (makespan). This issue is amplified when workflows are reused across recurring queries, making latency accumulate over time. This limits deployment in recurrent applications such as AI customer support and AI cloud troubleshooting, where users expect fast responses. To bridge this gap, we introduce a new problem, termed latency-aware workflow generation, where the objective is to minimize workflow makespan while aiming to retain downstream performance. We propose LAWA (Latency-Aware Workflow optimizAtion), a novel framework that reduces makespan via theoretically grounded graph edits targeting critical-path bottlenecks. By unifying a graph generator with this graph-editing procedure, LAWA supports both de novo workflow generation and refinement of existing ones. Empirical results across seven benchmarks demonstrate that LAWA significantly reduces makespan while achieving competitive task performance, supporting efficient reuse of multi-agent workflows for recurrent queries.

Building capable visual web agents demands precise grounding, long-horizon reasoning, and robust interaction with dynamic, real-world websites. Despite rapid progress, the strongest systems remain largely proprietary, while open agents still depend heavily on supervised post-training over large collections of curated web trajectories. This dependence creates a major scalability bottleneck: high-quality demonstrations are expensive to collect, and static datasets offer limited coverage of the diverse, ever-changing open web. Although online reinforcement learning (RL) has shown promise for text-based agents, its potential for training visual web agents directly on live websites remains largely unexplored. In this paper, we introduce OpenWebRL, an open framework for training visual web agents with online multi-turn RL on real websites. OpenWebRL covers the full training pipeline, including task selection, supervised warm-starting, live-browser execution, multimodal context management, trajectory success judging, and efficient multi-turn policy optimization. Using this framework, we train OpenWebRL-4B, which establishes a new open-source state of the art on challenging live-web benchmarks. With only 0.4K initialization trajectories and 2.2K open-ended training tasks, OpenWebRL-4B achieves 67.0% success on Online-Mind2Web and 64.0% on DeepShop, outperforming prior open agents of similar or larger scale and remaining competitive with proprietary systems including OpenAI and Gemini CUA. Beyond strong benchmark performance, OpenWebRL systematically identifies the key design choices that make online RL effective for visual web agents. Overall, our work offers a practical path toward building more capable, reproducible, and cost-efficient open web agents. We will release our training data, models, and code to support future research.