NeurIPS 2026 Papers

Multimodal large language models (MLLMs) have made rapid progress in general visual understanding, yet they still struggle with fine-grained instance-level consistency verification, where the goal is to determine whether two images depict the exact same physical object under varying viewpoints, illumination, and backgrounds. This task requires both a global understanding of the target instance and a precise examination of subtle local evidence, since semantically similar objects may differ only in small discriminative regions. To address this challenge, we propose \textbf{LocalAgent}, a collaborative agentic framework that integrates the complementary strengths of large and small models. Specifically, the MLLM first reasons from a global instance-level perspective to identify suspicious local regions that may determine the final verification result. These accurately localized regions are then delegated to a lightweight Local Evidence Verifier (LEV) toolkit for fine-grained appearance and geometric matching. The LEV toolkit consists of \textbf{Local Appearance Consistency (LAC)}, which provides illumination- and color-robust similarity estimation, and \textbf{Local Geometric Correspondence (LGC)}, which establishes reliable spatial correspondence under viewpoint changes. Rather than directly replacing the MLLM's reasoning, LEV returns structured similarity scores and comparative evidence in a form that the MLLM can effectively interpret for final decision-making. This design enables a coordinated large-small model collaboration: the MLLM contributes global semantic reasoning and region-level suspicion localization, while specialized local verifiers provide precise, invariant, and interpretable evidence for ambiguous cases. We further introduce an answer-dominant reinforcement fine-tuning (RFT) strategy that enables the policy to learn when verification is necessary. Experiments show that LocalAgent achieves a \textbf{+4.8\%} average improvement over direct-inference baselines, effectively narrowing the gap with closed-source models, while preserving the general multimodal capabilities of the underlying MLLM.

We study the problem of learning Gaussian mixture models under overparameterization. Prior work has shown that, while overparameterization is essential for avoiding spurious local optima and enables global recovery of the ground-truth model using the gradient-EM algorithm, it can dramatically slow the local rate of convergence. Under certain assumptions on the mixture weights, we show that a standard divergence measure minimized by statistical learning procedures possesses a manifold of slow growth on which the well-known Polyak stepsize reduces the loss geometrically. We then design a gradient-based method that converges to minimizers at a locally linear rate. Additionally, we show that our method converges to nearly optimal solutions—up to a natural misspecification threshold—for mixtures with arbitrary weights. At a high level, the method alternates between several “short” gradient descent steps that approach the manifold and “long” Polyak steps that contract the distance to minimizers. Our results suggest that slow convergence is not an intrinsic challenge of overparameterization, but can be overcome by exploiting the favorable structure of the loss landscape.

Remote sensing lithology interpretation is fundamental to geological surveys, mineral exploration, and regional geological mapping. Unlike general land-cover recognition, lithology interpretation is a knowledge-intensive task that requires experts to infer rock types from various features, e.g., subtle visual, making reliable automated interpretation highly challenging. Geological knowledge-guided large multimodal models offer new opportunities, yet their evaluation remains constrained by the lack of benchmarks that capture lithological annotations, multi-level geological semantics, and expert-informed assessment. Here, we propose LithoBench, a multi-level benchmark for evaluating geological semantic understanding in remote sensing lithology interpretation. LithoBench contains 10,000 expert-annotated interpretation instances across 12 representative lithological categories, including 4,000 multiple-choice and 6,000 open-ended tasks organized into five cognitive levels: Identification and Description, Comparative Analysis, Mechanism Explanation, Practical Application, and Comprehensive Reasoning. We further develop an expert-in-the-loop, knowledge-grounded semi-automated construction pipeline, coupling multi sub-processes, e.g., structured geological image descriptions, to enhance geological validity and evaluation reliability. Experiments with multiple large vision-language models reveal substantial limitations in geological semantic understanding, particularly on higher-order explanation, application, and reasoning tasks. Taken together, LithoBench establishes a dedicated testbed for advancing geological knowledge-guided multimodal models, supporting systematic model evaluation, domain-specific training and adaptation, and knowledge-enhanced reasoning toward expert-level lithology interpretation from remote sensing imagery.

As AI agents are given more autonomy in software engineering workflows, the risks grow if they pursue goals different from the ones their users intended. The field of AI control develops control protocols that prevent such harm without restricting the agent's ability to do useful work. We introduce \textbf{LinuxArena}, a control setting for testing such protocols, where agents operate directly on live, multi-service production environments. LinuxArena contains 10 public environments (with an additional 10 held out privately), providing 906 main tasks representing legitimate software engineering work and 92 side tasks representing safety failures such as data exfiltration and access-control bypassing, making it the largest and most diverse control setting for agentic software engineering to date. We demonstrate LinuxArena's utility by running sabotage and monitor evaluations: against a GPT-5 Nano trusted monitor at a 1% step-wise false positive rate, Claude Opus 4.6 achieves an undetected sabotage rate of 42%. We additionally release \textbf{LaStraj}, a dataset of human-crafted attack trajectories that achieves an undetected sabotage rate of 97% against the same monitor. Together, these results suggest meaningful headroom for both attackers and defenders, making LinuxArena a strong testbed for developing and evaluating future control protocols.

The extension of context windows in Large Language Models is typically facilitated by scaling positional encodings followed by Continued Pre-Training (CPT). While effective, this paradigm is notoriously data-hungry and computationally expensive, requiring massive long-text corpora to recalibrate the model to the shifted positional distribution. We propose LinearARD, a self-distillation method that restores Rotary Position Embedding (RoPE)-scaled students through attention-structure consistency with a frozen native-RoPE teacher. Rather than next-token prediction or opaque hidden-state matching, LinearARD aligns row-wise distributions of dense $Q/Q$, $K/K$, and $V/V$ self-relation matrices from the final attention layer to directly supervise attention dynamics. To remove the quadratic memory bottleneck of $n \times n$ relation maps, we introduce a linear-memory kernel that stores only per-token log-sum-exp statistics and recomputes logits in the backward pass to obtain exact Kullback-Leibler divergence gradients. Across LLaMA2-7B, LLaMA3-8B, and Mistral-7B-v0.1 extended to 32K context, LinearARD recovers 93.1\%/94.2\%/94.3\% of native short-context performance and achieves strong long-context robustness on RULER using only \textbf{4.25M} tokens---amounting to just 1.6\% (a $\sim$60$\times$ reduction) of the 256M-token budget required by state-of-the-art baselines. Under this severely constrained budget, CPT and LongReD remain near zero on RULER, demonstrating that relation-level restoration provides a substantially better efficiency-quality tradeoff.

Most physical systems are governed by nonlinear partial differential equations, yet the analytical tools that make linear systems transparent, such as eigenspectra, dispersion relations and modal decomposition, remain unavailable in nonlinear settings. We introduce Lie Generator Network-Koopman (LGN-KM), a neural operator that lifts nonlinear dynamics into a linear latent space and learns the continuous-time Koopman generator through the decomposition $L_k = S - D_k$, where $S$ is skew-symmetric (conservative coupling) and $D_k$ is positive-definite diagonal (mode-selective dissipation). The decomposition guarantees stability by construction and exposes the eigenstructure directly, making linear-systems analysis available on a nonlinear PDE. On 2D Navier-Stokes turbulence, the generator recovers a complete multi-branch dispersion relation and the viscous dissipation scaling $\mathrm{Re}(\lambda) \propto -|k|^2$ from trajectory data alone, with no physics supervision. The same architecture recovers the analogous diffusive scaling on FitzHugh-Nagumo reaction-diffusion without modification. Independently trained models at different regimes show matched gauge-invariant spectral structure. The architecture additionally enables long-horizon stability, $O(1)$ continuous-time evaluation, and physics--informed cross-regime model transfer.

Prior work has introduced techniques for detecting when large language models (LLMs) lie, that is, generate statements they believe are false. However, these techniques are typically validated in narrow settings that do not capture the diverse lies LLMs can generate. We introduce LIARS' BENCH, a testbed consisting of 72,863 examples of lies and honest responses generated by a range of open-weight models across seven datasets. Our settings capture qualitatively different types of lies and vary along two dimensions: the model's reason for lying and the object of belief targeted by the lie. Evaluating both black- and white-box lie detection techniques on LIARS' BENCH, we find that existing techniques systematically fail to identify certain types of lies, especially in settings where it's not possible to determine whether the model lied from the transcript alone. Overall, LIARS' BENCH reveals limitations in prior techniques and provides a practical testbed for guiding progress in lie detection.

Robust and accurate neural decoders are integral to the development of neurotechnological applications such as brain-computer interfaces and closed-loop experiments. Recent work has shown that tokenizing neural data at the resolution of individual spikes facilitates multi-session pretraining and delivers state-of-the-art decoding performance. However, these spike-based models are currently restricted to supervised learning (SL) regimes, limiting both pretraining and finetuning to datasets with paired behavioural labels. To address this, we introduce MOJO ($\textbf{M}$asked aut$\textbf{O}$encoder-based $\textbf{JO}$int training), a training framework designed for spike-tokenizing models that jointly leverages self-supervised learning (SSL) via masked autoencoding and SL objectives for better decoding performance and interpretability. We evaluate MOJO on three intracortical spiking datasets—monkey motor cortex across various reaching tasks, multi-regional mouse recordings during vision and cognitive decision making tasks—demonstrating superior performance to purely SL-trained models. This improvement is especially notable when training with limited labelled data, specifically in the few-shot finetuning regime where only a small amount of labelled data is available to adapt a model to a new recording session. The incorporation of SSL also yields more interpretable neuronal representations, improving performance on analyses such as brain region classification and spike-statistics prediction despite the lack of explicit optimization for these tasks. We then show that MOJO generalizes beyond spiking data using human electrocorticography (ECoG) during speech articulation. We show that MOJO continues to outperform purely SL-trained models and achieves performance comparable to neuro-foundation models (NFMs) built specifically for continuous signals. Overall, augmenting spike-tokenizing models with SSL improves their performance in label-impoverished settings and enables the use of unlabelled data across various tasks and species, and while generalizing to other neural modalities. These results suggest a path towards more flexible and scalable data usage when training NFMs.

Scalar quantization of large language models (LLMs) is fundamentally limited by information-theoretic bounds. While vector quantization (VQ) overcomes these limits by encoding blocks of parameters jointly, practical implementations must avoid the need for expensive lookup mechanisms or other explicit codebook storage. Lattice approaches address this through highly structured and dense packing. This paper explores the Leech lattice, which, with its optimal sphere packing and kissing configurations at 24 dimensions, is the highest dimensional lattice known with such optimal properties. To make the Leech lattice usable for LLM quantization, we extend an existing search algorithm based on the extended Golay code construction, to i) support indexing, enabling conversion to and from bitstrings without materializing the codebook, ii) allow angular search over union of Leech lattice shells, iii) propose fully-parallelisable dequantization kernel. Together this yields a practical algorithm, namely Leech Lattice Vector Quantization (LLVQ). LLVQ delivers state-of-the-art LLM quantization performance, outperforming recent methods such as Quip\#, QTIP, and PVQ. These results highlight the importance of high-dimensional lattices for scalable, theoretically grounded model compression.

Web agents promise to automate consequential operations on enterprise web systems, yet the benchmarks used to evaluate them score correctness on surface-level proxies: DOM/URL predicates, action-trace matchers, or vision-language verdicts on a closing screen. These proxies are inadequate for enterprise resource planning (ERP) systems, where every action commits to a transactional ledger and the criterion of correctness is what the ledger now records, not what the page now renders. We argue that ERP web operations should be evaluated against what a run actually wrote to the relational backend, with the server-side operation trace recorded alongside the outcome to provide the audit provenance that enterprise governance requires. We introduce Ledger, a path-validated, database-grounded benchmark for browser agents on a production-grade open-source ERP: 424 oracle-certified task instances across 53 functional modules, scored by an Atomic Edit Set validator (field-level $F_1$ against a PostgreSQL oracle, under a typed normalization function) paired with a Canonical Operation Tracer (server-side instrumentation of the ERP’s JSON-RPC dispatch). Each episode runs under pg_restore snapshot isolation; no language-model judge is invoked; three formal guarantees (score determinism, episode isolation, tracer completeness) make scores auditable and exactly replayable. A cross-paradigm evaluation of seven contemporary browser agents shows Ledger discriminates architectures sharply, with task-success rate spanning 81.6% down to 13.7% across the roster while long-horizon enterprise workflows remain far from saturated.

Recently, Antoniadis et al. (ICLR 2025) proposed a framework for incorporating predictions to approximate NP-hard selection problems. Despite its simplicity, this approach tightly matches theoretical lower bounds, making its generalization highly compelling. We address an open question raised in the work of Antoniadis et al., concerning the extension of this approach to other important problems outside the class of selection problems, such as scheduling. We develop a learning-augmented algorithm for the makespan minimization problem on unrelated machines, denoted by $R||C_{\max}$. By using predictions of heavy job assignments, we achieve a polynomial-time $(1+\varepsilon)$-approximation for accurate predictions that smoothly degrades to a worst-case 2-approximation as the error increases. We conclude our work with an empirical analysis of our method.

Boolean satisfiability (SAT) provides a foundation tool for cryptographic key recovery by encoding ciphers into CNF or ANF representations. However, heuristic solvers and their neural-enhanced variants often degrade significantly on cryptographic instances due to pronounced structural symmetry, a large number of intermediate variables, and complex algebraic dependencies. Existing neural approaches—ranging from end-to-end prediction to solver-integrated heuristics—face challenges in scalability, assignment accuracy, or computational efficiency. In this paper, we propose a unified neural-guided enumerative SAT framework for cryptographic key recovery. It performs a single forward neural guidance to identify a subset of $k$ critical variables, followed by enumeration over their assignments before invoking a heuristic SAT solver. This design effectively reduces the combinatorial search space while keeping neural overhead minimal. We further introduce a taxonomy of neural guidance across data and model capability regimes, including supervised selection with cryptographic priors, uncertainty-driven selection with assignment prediction, and robust fallback strategies using the model trained on general SAT datasets. Experiments on 10 SAT solvers and 2 cube-and-conquer strategies over SAT4CryptoBench and SAT Competition benchmarks demonstrate up to $5\times$ speedup and approximately 2× average improvement on cryptographic instances, while maintaining better performance on general SAT datasets. These results highlight the effectiveness and generalization of this framework, illustrating its potential to bridge machine learning and SAT solving in cryptanalysis tasks.

Scaling neural solvers to large Vehicle Routing Problems (VRPs) runs into two recurring difficulties. To stay within compute budgets, scalable solvers tend to rely on partitioning, local candidate restriction, or staged decisions, which limit the global structure that ultimately drives solution quality. To improve the final solution, many neural pipelines fall back on a classical search, but use it as a one-shot post-processor. The model predicts, search repairs, and no sustained feedback is formed between them. We propose $\textit{LSSL}$ (Learning to Search, Searching to Learn), a closed-loop learning-search framework for large-scale VRP that addresses both difficulties in one framework. LSSL predicts a search-friendly guidance heatmap on a sparse candidate graph. A classical heuristic backend then uses this heatmap to refine the incumbent solution, and the structural state returned by the backend is fed back to recondition the model. As a result, learning and search interact within a closed loop, rather than operating as two detached stages. Built on a sparse diffusion transformer over an O($\textit{NK}$) candidate graph, the loop scales to ultra-large instances on a single consumer-grade GPU without hard decomposition. Experiments on large-scale TSP and CVRP benchmarks demonstrate that LSSL achieves superior scalability, efficiency, and solution quality. Ablation studies further reveal that the closed learning–search loop accounts for a substantial portion of the observed performance gains.

Reinforcement Learning with Verifiable Rewards (RLVR) enhances large language model (LLM) reasoning, yet growing evidence indicates an \emph{exploration ceiling}: they tend to reweight existing solution traces and produce low-diversity rollouts. This restricts the discovery of novel solution perspective and weakens out-of-distribution generalization. We address this limitation by directly perturbing the rollout policy's parameters while updating the clean policy model as usual, an approach that achieves better temporal consistency and yields more complex behavior patterns. To stabilize learning from these perturbed rollouts, which are inherently off-policy, we incorporate truncated importance sampling. Furthermore, we introduce a lightweight, dynamic noise scheduler based on semantic diversity and model self-certainty to optimally adjust the noise scale. Instantiated on GRPO, our method (PSN-GRPO) demonstrates its efficacy through four key contributions: (1) it improves high-budget pass@$k$, increases semantic and operational diversity, increases CoT consistency, and remains complementary to exploration-oriented RLVR techniques; (2) it validates efficacy across multiple models, including Qwen2.5, Qwen3, and Llama-3.1; (3) it shows robust performance on out-of-distribution science and coding benchmarks; and (4) it uncovers novel solution perspectives for problems the original model could not solve, as shown by qualitative analysis.

Benders decomposition (BD) is a widely used solution approach for solving two-stage stochastic programs arising in real-world decision-making under uncertainty. However, it often suffers from slow convergence as the master problem grows with an increasing number of cuts. In this paper, we propose Reinforcement Learning for BD (RLBD), a framework that adaptively selects cuts using a neural network-based stochastic policy. The policy is trained using a policy gradient method via the REINFORCE algorithm. We evaluate the proposed approach on a two-stage stochastic electric vehicle charging station location problem and compare it with vanilla BD and LearnBD, a supervised learning approach that classifies cuts using a support vector machine. Numerical results demonstrate that RLBD achieves substantial improvements in computational efficiency and exhibits strong generalization to problems with similar structures but varying data inputs and decision variable dimensions.

Understanding how complex molecular systems transition between metastable states is a central challenge in computational chemistry and biophysics. A key tool for characterizing these transitions is the committor function, defined as the probability that a trajectory initiated from a given configuration reaches one state before another, which encodes detailed mechanistic information about transition pathways. First, we curate a public benchmark of empirically determined committor values for alanine dipeptide. Second, we develop a "committor-in-the-loop" framework that combines a self consistent loss function with weighted ensemble (WE) simulation: WE adaptive bins are biased by the learned committor, which is in turn trained on WE samples. Across a two-channel 2D system and alanine dipeptide settings, our WE-based framework consistently outperforms greedy baselines, demonstrating the importance of principled exploration. Together, the benchmark and framework provide both a standard for evaluating committor learning methods and a new method for studying rare transitions in high-dimensional molecular systems.

In-context reinforcement learning (ICRL) leverages the in-context learning capabilities of transformer models (TMs) to efficiently generalize to unseen sequential decision-making tasks without parameter updates. However, existing ICRL methods rely on explicit reward signals during pretraining, which limits their applicability when rewards are ambiguous, hard to specify, or costly to obtain. To overcome this limitation, we propose a new learning paradigm, \emph{In-Context Preference-based Reinforcement Learning} (ICPRL), in which both pretraining and deployment rely solely on preference feedback, eliminating the need for reward supervision. We study two variants that differ in the granularity of feedback: \emph{Immediate Preference-based RL} (I-PRL) with per-step preferences that generalize dueling bandits, and \emph{Trajectory Preference-based RL} (T-PRL) with trajectory-level comparisons. We first show that supervised pretraining, a standard approach in ICRL, remains effective under preference-only context datasets, demonstrating the feasibility of in-context solving unseen tasks using only preference signals. To further improve data efficiency, we introduce alternative preference-native frameworks for I-PRL and T-PRL that directly optimize TM policies from preference data without requiring reward signals nor optimal action labels. Experiments on dueling bandits, navigation, and continuous control tasks demonstrate that ICPRL enables strong in-context generalization to unseen tasks, achieving performance comparable to ICRL methods trained with full reward supervision.

Recent latent diffusion methods jointly model multiple representations of an image, denoising them with asynchronous noise schedules in which one representation temporally leads another. However, existing asynchronous schedules are often hand-designed, relying on grid search over simple function classes. We propose to learn the asynchronous schedule directly. We parameterize the schedule as a convex monotone bijection $f : [0,1] \to [0,1]$, where convexity together with $f(0)=0$ and $f(1)=1$ guarantees the desired leading-representation property by construction while still admitting a wide family of schedule shapes. A short probe stage jointly optimizes the schedule and diffusion model under a mild speed regularizer; the resulting smooth schedule is averaged over the stable probe window, frozen, and reused for full training, introducing no additional overhead during the main training stage. On ImageNet 256$\times$256, our learned schedule reaches unguided FID 2.37 at 1M iterations and FID 1.05 with AutoGuidance at 200 epochs, outperforming the best hand-tuned baseline trained for four times longer. Code is available at \url{https://anonymous.4open.science/r/LAS_public-01E4/}.

Understanding mouse behavior at scale is a foundational problem in neuroscience, with two core tasks: classifying frames into known behaviors and segmenting recordings into recurring patterns without labels. Pose-based methods are the standard approach but face fundamental limitations: pose coordinates capture only skeletal information, discard environmental context, and degrade under frequent occlusions in social scenarios. Mouse videos can provide the visual context that pose lacks, yet not all frames benefit equally, and adding visual features uniformly to every frame is suboptimal. We find that a pose-based motion encoder, trained with auxiliary supervision from videos, can identify where it struggles: with a discrete representation, the encoder learns a codebook of recurring patterns, and frames whose motion does not fit this codebook produce large quantization residuals. We show that these high-residual frames are where visual context tends to help most: residual-guided frame selection consistently outperforms uniform selection across budgets, and often exceeds dense visual processing. We therefore propose ResiFuse, a framework that pretrains a motion encoder on pose with an auxiliary cross-modal loss and integrates vision context only on high-residual frames at fine-tuning time. We evaluate ResiFuse on three mouse behavior datasets and show improvements over pose- and video-based baselines on most tasks, with the largest gains on the most socially complex dataset.