NeurIPS 2026 论文列表

Pre-training neural operators on diverse PDE datasets has emerged as a promising paradigm for building general-purpose surrogate models in scientific machine learning. However, the **inherent complexity** and **structural diversity** of PDE solution operators make multi-PDE pre-training fundamentally difficult. Existing approaches address this mainly by enlarging model capacity, while the target solution operators themselves remain unchanged. Inspired by classical numerical analysis---where a problem-tailored *operator transformation* reformulates a complex PDE into a numerically easier equivalent---we propose to similarly reformulate the target solution operators, turning a heterogeneous set of complex, structurally divergent operators into a simpler and better-aligned equivalents. Since different PDEs admit different simplifications, the transformation must be *adaptive and input-dependent*, so that a single neural operator can approximate the entire family jointly. We instantiate this idea as AOT-POT (**A**daptive **O**perator-**T**ransformation for **P**re-training **O**perator **T**ransformer), which realizes such a transformation by expanding the hidden representation into multiple parallel streams, aggregating and redistributing them with input-dependent weights before and after each sub-layer, and mixing streams through Sinkhorn-projected doubly stochastic matrices for stable training. Together, these mechanisms reformulate the diverse, complex solution operators into a simpler equivalents that a single architecture can approximate jointly. Empirically, AOT-POT achieves state-of-the-art results on 12 PDE benchmarks with only 3% additional parameters, reducing the relative L2 error by up to 77.6% (40.9% on average). Fine-tuning further reduces L2 error by up to 92% on in-domain PDEs and 89% on out-of-domain PDEs, confirming that adaptive operator transformation is an orthogonal and effective axis for advancing PDE foundation models, beyond merely scaling model capacity.

Scaling network depth has been a central driver behind the success of modern foundation models, yet recent investigations suggest that deep layers are often underutilized. This paper revisits the default mechanism for deepening neural networks, namely residual connections, from an optimization perspective. On a motivating example, rigorous analysis proves that the layout of residual connections can fundamentally shape convergence behavior, and even induces an *exponential* gap in convergence rates. Prompted by this insight, we introduce adaptive neural connection reassignment (ANCRe), a principled and lightweight framework that parameterizes and learns residual connectivities from the data. ANCRe adaptively reassigns residual connections with negligible computational and memory overhead (<1%), while enabling more effective utilization of network depth. Extensive numerical tests across pre-training of large language models, diffusion models, and deep ResNets demonstrate consistently accelerated convergence, boosted performance, and enhanced depth efficiency over conventional residual connections.

Multimodal large language models (MLLMs) achieve impressive performance on audio-visual question answering, but correct answers do not necessarily imply perceptually grounded reasoning. Models may exploit linguistic priors or dataset shortcuts without attending to the visual regions and audio events that actually justify their predictions. Existing benchmarks predominantly evaluate final answer accuracy, providing limited insight into whether models truly “see” or “hear” the evidence required for reasoning. We introduce ANCHOR, a benchmark and evaluation framework for auditing perceptual grounding in multimodal reasoning. ANCHOR requires models to produce grounded chain-of-thought explanations that explicitly reference audio-visual evidence, including representative frames, spatial bounding boxes, and salient audio cues. To build a reliable gold standard, we combine automated annotation generation with a human-in-the-loop refinement pipeline, producing 224 human-verified videos and 975 question–answer pairs with aligned reasoning and localization annotations from 2.3K videos and 8.2K QA pairs. We further propose a metric and evaluation protocol that jointly measure answer correctness and reasoning-grounding alignment, complemented by multi-judge scoring of hallucination, logical divergence, final answer, and a token-based conciseness measurement. Experiments on nine state-of-the-art MLLMs reveal a substantial faithfulness gap: models with strong answer performance often produce explanations that are only weakly grounded in the underlying perceptual evidence. Ablation results confirm the importance of explicit grounding cues: removing bounding boxes reduces accuracy by 7.7 points, and performance drops from 57.7% with full cues to 16.1% in the audio-only setting. These findings show that answer-only evaluation is insufficient for multimodal reasoning and position ANCHOR as a new testbed for developing systems that are accurate, interpretable, and trustworthy.

Modern deep learning commonly relies on AdamW with prescribed learning rate schedules, but recent works challenge both components: Schedule-Free optimization removes explicit schedules via iterate averaging, and Muon improves the update geometry by orthogonalizing momentum for matrix parameters. Despite Muon's strong empirical performance, its underlying mechanism remains partially understood. We study Muon through the river-valley loss landscape, where useful training progress occurs along a flat, low-curvature bulk subspace (the river), while high-curvature dominant directions form steep valley walls that induce oscillations. We empirically show that while Muon's orthogonalization accelerates river progress by increasing the bulk component, it also amplifies dominant-direction noise, causing oscillatory trajectories. Building on this, we propose Anytime MUon with Stable gradient Evaluation (AMUSE), which integrates Muon's rapid bulk progress with the stabilizing effect of Schedule-Free averaging. AMUSE uses a time-varying interpolation coefficient that initially evaluates gradients near the fast Muon sequence for rapid adaptation, then gradually shifts toward the stable averaged sequence to suppress valley-wall oscillations. As a result, AMUSE requires no learning rate schedules and supports anytime training. Across vision tasks and large language model pretraining, AMUSE consistently improves the performance-iteration Pareto frontier over (Schedule-Free) AdamW and Muon.

Multimodal Large Language Models (MLLMs) often exhibit significant modality preference, which is a tendency to favor one modality over another. Depending on the input, they may over-rely on linguistic priors relative to visual evidence, or conversely over-attend to visually salient cues over textual facts. Prior work has applied a uniform steering intensity to adjust the modality preference of MLLMs. However, strong steering can impair standard inference and increase error rates, whereas weak steering is often ineffective. Since steering sensitivity varies substantially across instances, a single global strength is difficult to calibrate. To address this, we introduce an instance-aware diagnostic metric Modality Contribution Ratio (MCR) that quantifies each modality’s information contribution and reveals sample-specific susceptibility to steering. Building on this signal, we propose a scaling strategy and a learnable module for instance-aware control of modality preference. Experiments show that AMPS outperforms conventional steering on $MC^2$ by improving preference control with lower generation collapse, and improves MLLM performance on general multimodal QA dataset such as MM-Vet v2.

Amorphous (disordered) materials require simulation cells with at least hundreds to thousands of atoms to accurately capture their diverse local atomic environments, compared to crystalline materials that can be described by unit cells containing a few to hundreds of atoms. To advance the design of amorphous materials with desired properties and facilitate the exploration of their vast design space, generative inverse design has emerged as a promising approach. It aims to directly output materials with properties closely aligned with the desired ones using probabilistic generative models conditioned on desired properties, which can be more resource efficient than the traditional trial-and-error approach. However, due to the inherent stochasticity of probabilistic generative models, when element assignments are unconstrained, a large portion of generated materials may be charge unbalanced, and no existing methods can effectively mitigate this limitation. In this work, we propose AMGenC, a new generative inverse design method for amorphous materials that can guarantee the generation of charge balanced samples, with minimal additional computational overhead and without sacrificing inverse design accuracy. AMGenC achieves this through an element noise that gives the generation process a starting point centered around charge balance, and the combination of a per-step soft projection and a final discrete projection for steering the elements toward exact charge balance throughout the generation. We perform extensive experiments on two amorphous materials datasets. Experimental results provide evidence that AMGenC achieves its design goal.

Time series forecasting models are increasingly scaled through large Transformer backbones, yet most existing approaches process all series through a shared dense computation path despite substantial heterogeneity in temporal structure. Mixture-of-Experts (MoE) offers a natural alternative by enabling conditional computation, but standard MoE routing leaves expert specialization weakly identified and often unstable during downstream adaptation. We propose AME-TS, a structure-guided sparse time series foundation model that aligns expert routing with interpretable temporal structure. AME-TS first uses a lightweight regime predictor to estimate series-level descriptors, including forecastability, seasonality, trend, and sparsity, and maps them to a soft structural prior over experts. This series-level prior guides token-level routing during training, encouraging structure-aligned specialization. On the GIFT-Eval benchmark, AME-TS delivers a strong accuracy-efficiency tradeoff across model scales: it substantially outperforms existing time series foundation models at small model scales and remains competitive with the strongest models at larger scales, while activating substantially fewer parameters through sparse routing. We further show that AME-TS learns more interpretable routing geometry and substantially more stable expert specialization than standard MoE during fine-tuning on the M5 dataset. These results suggest that structure-aware routing is an effective and reliable way to realize the benefits of sparse expert models for time series forecasting.

Domain specialization of large language models (LLMs) often improves target-domain performance but degrades broad capabilities. Model merging is an attractive training-free alternative, yet common parameter-space strategies (for example, interpolation and sparsified averaging) provide limited control over task-specific interference. We introduce Adaptive Model Alignment via Ranked Inherited Subspaces (AMARIS), a covariance-driven framework that transfers specialist updates only along selected activation directions. AMARIS formulates merging as budgeted subspace inheritance: it maximizes specialist activation capture while constraining base-activation deviation, then builds a low-rank projection gate from ranked generalized eigendirections under an explicit preservation budget. This yields a single static merged checkpoint that concentrates transfer in high-utility, low-interference directions. We evaluate AMARIS on Qwen3-based merges (8B and 32B) across finance, instruction-following, and multilingual SEA specialization. In our evaluated settings, AMARIS reaches Pareto operating points that are competitive with strong training-free baselines, including 98.37\% specialist retention with 95.76\% core retention (finance), 103.49\% core retention with 90.28\% specialist retention (instruction following), and 93.69\% specialist retention with 99.77\% core retention (SEA). These results support subspace-constrained merging as a practical route to compositional capability integration without additional training.

Despite the critical role of temporal reasoning in Large Language Models (LLMs), current synthetic benchmarks fall short: they either introduce information leakage or, upon addressing this issue, merely assess questions with explicit time points, failing to rigorously evaluate implicit temporal reasoning capabilities. To bridge this gap, we propose a formally grounded evaluation framework, ALTER, based on Allen’s Interval Algebra. By combining basic relations into complex networks and converting these structures into natural language forms through an automated pipeline, we construct a validated benchmark of 2,500 question-answer pairs, ensuring a controllable and scalable evaluation environment. We conduct experiments on a representative selection of LLMs. Empirical evaluations on diverse LLMs yield three key findings: (1) identifying performance decline of LLMs in highly complex scenarios involving dense events; (2) isolating complex logical interactions—rather than linguistic comprehension—as an unresolved bottleneck; and (3) revealing a critical evaluation bias induced by narrative chronology, with LLMs exploiting textual shortcuts. In summary, these findings reveal the blind spots of current evaluation paradigms, providing a rigorous foundation for the robust evaluation of complex temporal reasoning.

Vision-language-action (VLA) models remain constrained by the scarcity of action-labeled robot data, whereas action-free videos provide abundant evidence of how the physical world changes. Latent action models offer a promising way to extract such priors from videos, but reconstruction-trained latent codes are not necessarily suitable for policy generation: they may predict future observations while lacking the structure needed to be reused or generated coherently with robot actions. We introduce \textbf{ALAM} (\textbf{A}lgebraic \textbf{L}atent \textbf{A}ction \textbf{M}odel), an Algebraically Consistent Latent Action Model that turns temporal relations in action-free video into structural supervision. Given frame triplets, ALAM learns latent transitions that are grounded by reconstruction while being regularized by composition and reversal consistency, encouraging a locally additive transition space. For downstream VLA learning, we freeze the pretrained encoder and use its latent transition sequences as auxiliary generative targets, co-generated with robot actions under a joint flow-matching objective. This couples structured latent transitions with flow-based policy generation, allowing the policy to exploit ALAM's locally consistent transition geometry without requiring latent-to-action decoding. Representation probes show that ALAM reduces additivity and reversibility errors by 25--85$\times$ over unstructured latent-action baselines and improves long-horizon cumulative reconstruction. When transferred to VLA policies, ALAM raises the average success rate from 47.9\% to 85.0\% on MetaWorld MT50 and from 94.1\% to 98.1\% on LIBERO, with consistent gains on real-world manipulation tasks. Ablations further confirm that the strongest improvements arise from the synergy between algebraically structured latent transitions and joint flow matching.

We introduce AIRA-Compose — a framework that enables AI research agents to autonomously explore and discover novel neural architectures. AIRA-Compose leverages the previously-proposed Composer abstraction to define a combinatorial design space over fundamental model primitives (Attention, MLP, and Mamba), then uses a guided search policy to efficiently navigate this space for novel neural architecture design. Our approach operates in two stages: (1) agents iteratively designs and evaluates candidate architectures at the million-parameter scale, then (2) top-performing candidates are scaled to billion parameters for pre-training. Overall, AIRA-Compose discovers 14 novel architectures spanning two families — AIRAformers (Transformer-based) and AIRAhybrids (Transformer-Mamba Hybrid-based). When pre-trained at 1B scale under a fixed token budget, agent-discovered top-performing architectures consistently outperform both Llama 3.2 and Composer-found alternatives. On downstream tasks, AIRAformer-D and AIRAhybrid-D improve accuracy by 2.4% and 3.8% over Llama 3.2, respectively. AIRA-Compose also finds novel model architectures that achieve steeper, more efficient compute-optimal scaling frontiers. AIRAformer-C scales 54% and 71% faster than Llama 3.2 and the best Composer-found Transformer, while AIRAhybrid-C scales 23% and 37% faster than the modified Nemotron-2 and the best Composer-found hybrid, respectively. For the first time, AIRA-Compose demonstrates that AI research agents can discover hybrid architectures that surpass hand-designed baselines on the accuracy–compute frontier. It establishes a flexible paradigm for LLMs to discover next generation foundation models, marking a step towards recursive self-improvement.

Existing research has identified three structural performance bottlenecks in AI research agents: (1) synchronous single-GPU execution constrains sample throughput, limiting the benefit of search; (2) a generalization gap where validation-based selection causes overfitting and performance to degrade over extended search horizons; and (3) the limited capability of fixed, single-turn LLM operators imposes a ceiling on search performance. We introduce AIRA$_2$, which addresses these bottlenecks through three architectural choices: an asynchronous multi-GPU worker pool that increases experiment throughput linearly; a Hidden Consistent Evaluation protocol that delivers a reliable evaluation signal; and ReAct agents that dynamically scope their actions and debug interactively. On MLE-bench-30, AIRA$_2$ achieves a mean Percentile Rank of 81.5% at 24 hours and 83.1% at 72 hours, outperforming the strongest baseline, which achieves 72.7%. On AIRS-Bench, AIRA$_2$ exceeds human state-of-the-art on 6 out of 20 diverse research tasks. Ablations confirm that each architectural component is necessary, that performance follows a predictable scaling law that transfers across LLM backbones, and that the "overfitting" reported in prior work was driven by evaluation noise rather than true data memorization.

Image-text offset alignment, which refers to the consistency between visual transformation directions and their corresponding textual transformation directions, has become an important relational property in multimodal contrastive representation space (e.g., CLIP or SigLIP). This property is widely utilized in text-guided generative modeling tasks, such as generative model domain adaptation and text-guided Image-text offset alignment, which refers to the consistency between visual transformation directions and their corresponding textual transformation directions, has become an important relational property in multimodal contrastive representation spaces such as CLIP and SigLIP. This property plays a central role in text-guided generative modeling tasks, including generative model domain adaptation and text-guided image editing, where textual offsets are used to guide visual transformations. These methods fundamentally rely on the assumption that image and text offsets are well aligned, such that textual transformation directions can provide reliable guidance for corresponding visual transformations. However, the validity of this assumption has not been systematically examined. **In this work**, we question this foundational assumption by conducting a comprehensive empirical analysis of image-text offset alignment in multimodal contrastive representation space. Our findings reveal not only noticeable offset misalignment but also a meaningful positive correlation between image-text offset misalignment and semantic concept distance across six large datasets and eight contrastive vision-language models. Based on this discovery, we propose Adaptation with Iterative Refinement (AIR), a method that iteratively refines text offsets through anchor sampling and our proposed concept description learning to reduce image-text offset misalignment and improve guidance accuracy. Comprehensive experiments on zero-shot generative model domain adaptation and text-guided image editing, including qualitative, quantitative, and user studies, consistently show that AIR enables state-of-the-art performance in these tasks. **Code and additional experiments are available in the supplementary material.**

Multi-Agent Debate (MAD) improves reasoning on multimodal tasks, but its accuracy and token efficiency depend on how agents interact during debate. A largely overlooked design choice is which interaction modalities agents use to exchange evidence. Existing methods rely on fixed text- or graph-based interaction, which fails to convey fine-grained multimodal evidence, degrading accuracy while inflating token cost due to verbose descriptions. To address this, we propose Adaptive Interaction in Multi-Agent Debate (AIM), an adaptive framework that dynamically selects the best combination of interaction modalities for each instance. Beyond text and graph, AIM introduces task-dependent modality interaction, where agents exchange targeted regions of interest from the task-specific multimodal input, such as image regions, audio segments, and spatio-temporal clips. To determine which combination is the best for each instance, AIM first generates a structured baseline response, extracts interpretable routing features, and finally uses a lightweight router to select a modality combination that avoids both under-fusion (i.e., agents miss decisive evidence) and over-fusion (i.e., redundant modalities inflate token cost) risks. Across eight multimodal question answering (QA) benchmarks of Visual-QA, Audio-QA, and Video-QA, AIM achieves the highest accuracy on all datasets, improving upon the best single-modality baseline by up to 8.9% while reducing token cost by up to 53.4% relative to the best fixed-modality baseline.

Generative artificial intelligence (AI) is increasingly integrated into the online platforms where humans exchange opinions; large language models (LLMs) now polish users' posts on LinkedIn and provide context for content shared on X. While prior work has shown that AI can express biased opinions and shape individuals' opinions during human-AI interactions, less attention has been paid to its influence on collective opinion formation when mediating human-to-human communication. We address this gap via a combination of empirical and theoretical analyses. We show empirically that LLMs from multiple popular families introduce directional biases when instructed to edit human-written texts on contested topics, for example, nudging texts in favor of gun control and against atheism. Building on this observation, we introduce a mathematical model of opinion dynamics in which an AI system sits between users on a social network, transforming the opinions they express and perceive. By analytically characterizing the equilibrium of this model and performing simulations on real social network data, we show that biases introduced by AI in human-to-human communication can be amplified through the network and shift collective opinion in their direction. In light of these findings, we investigate whether such biases are controllable by online platforms. We audit the "Explain this post" feature on X and find evidence of pro-life bias in Grok's outputs on abortion-related content, which we trace back to specific design choices.

When does an AI assistant improve human decision-making, and when does it hurt? We consider the setting in which a human worker makes a binary decision by observing her own signal and receiving a binary or probabilistic recommendation from an AI. We develop a behavioral model which considers both her belief regarding the overlap of her signal with the AI as well as the trust she has in the AI when considering its recommendation. The model yields a phase diagram in AI capability and signal overlap, partitioning the parameter space into complementarity, impairment, and automation regions. A worker who neglects signal overlap (correlation neglect) can experience performance loss when incorporating AI into her decision and is eventually dominated by AI alone as AI capability grows, with the complementarity range narrowing as overlap rises. Trust calibration shifts region boundaries: undertrust shrinks the impairment region but expands automation, while overtrust expands impairment but extends complementarity to be preferred at higher AI capability levels. Applying the framework to ChatBench (643 workers, GPT-4o and Llama-3.1-8b), AI assistance raises accuracy by 21 percentage points, but workers undertrust the AI by roughly a factor of four. The model yields design insights linking AI deployment choices, worker behavioral parameters, and outcome quality.

We argue that in multiple areas of AI for drug discovery (AIDD), deep learning models are not learning the meaningful biological or chemical features they were hypothesised to capture, but instead learn non-generalisable features, for example, from dataset biases. To address this, we propose the systematic use of misaligned baselines. We define misaligned baselines as models that rely on signals purposely misaligned with the intended learning objective. Rather than modelling the underlying biology or chemistry directly, these baselines draw on reductionist sources of information, heavily perturbed input features, or heuristic models. Competitive performance of such baselines reveals when models are not learning the biologically meaningful representations they were designed to learn. By examining case studies across multiple branches of AIDD, we demonstrate that misaligned baselines have consistently exposed such failure modes and crucially informed the evaluation and improvement of these models. We argue that adopting them as standard practice will help to ensure that progress in AIDD reflects genuine advances rather than artefacts of data-generating processes or evaluation design.

Capability evaluations aim to surface dangerous model behaviors before deployment, but their reliability depends on the assumption that hidden capabilities can be elicited. We show this assumption does not hold under adversarial conditions by constructing backdoor attacks that embed encrypted neural networks within host model weights, decrypting and executing them only upon receiving a secret trigger. Using digital lockers, these hidden circuits remain provably hard to elicit and interpret under standard cryptographic hardness assumptions, even given full access to model weights, extending prior work from hiding fixed strings to arbitrary computations. We implement our constructions in PyTorch and empirically validate resistance to supervised fine-tuning on a small chemical reaction prediction task - a proxy for CBRN-relevant capabilities. Our results reveal a limit of capability audits. We release our models to support the development of stronger defenses.

AI models deployed in critical domains, such as AI safety research, may subtly sabotage our efforts due to misalignment. _Sandbagging_ is a form of sabotage in which an AI intentionally underperforms on the task given to it. It is particularly pernicious on _fuzzy_ tasks, i.e. tasks which are hard to grade or require intuition. To understand sandbagging on fuzzy tasks, we introduce a novel AI control framework that considers sandbagging as an adversarial game between a blue team and a red team. The blue team uses a weak trusted model to construct a weak score against which they would train a strong, potentially sandbagging model to remove the sandbagging if it were present. The red team then tries to find model behaviors that are rated highly by the weak score, and thus might not be trained out, but actually correspond to poor performance. We test our framework on the task of writing experimental proposals for research questions from recent ML papers. We use a language model with access to the original paper as a proxy "ground-truth" scorer. Our red team discovers sandbagging behaviors using multi-objective evolutionary prompt optimization. We show that Opus 4.6 can write proposals that are worse according to the ground truth proxy than those of GPT-OSS-20B, while the weak scorer rates them as highly as the best proposals from Opus 4.6. To mitigate the threat of sandbagging, we propose an adversarial optimization algorithm for the blue team that discovers more robust prompts for the weak model. This algorithm produces a blue team prompt that our red team optimization fails to exploit.