NeurIPS 2026 论文列表

Scene text encodes high-density semantic information, raising privacy risks for automated vision systems. Existing privacy-preserving adversarial methods mainly target Scene Text Recognition (STR) by inducing character-level misrecognition, yet text regions remain detectable, enabling manual inspection or downstream recovery. We argue that stronger privacy requires suppressing Scene Text Detection (STD) during localization, hiding text as background to bypass subsequent OCR pipelines. To this end, we propose **AR-Attacker** (**A**ttention-guided **R**einforcement learning text **Attacker**), a black-box attack framework that generates sparse, visually imperceptible perturbations to effectively suppress STD outputs. We formulate the attack as a Markov Decision Process (MDP) and design an attention-guided action space, which leverages a frozen surrogate model to focus perturbations on salient text regions. Furthermore, AR-Attacker employs a discrete-continuous hybrid policy optimized with Proximal Policy Optimization (PPO), which jointly selects perturbation locations and magnitudes. Empirical results show that AR-Attacker surpasses state-of-the-art baselines by 30% in text removal rate while simultaneously reducing query counts by 40%. Remarkably, the framework maintains high visual fidelity ($\textit{PSNR} > 45$ dB), advancing the "visible to humans, invisible to machines" privacy paradigm through a robust RL-based approach.

Generative molecular optimization aims to design molecules with properties surpassing those of existing compounds. However, evaluating candidate molecules is expensive, so sample efficiency, i.e., generating optimized molecules within a fixed evaluation budget, is essential. Moreover, in the offline setting, where a surrogate model approximates candidate evaluation, sample inefficiency compounds with surrogate error, further limiting performance. To address these challenges, we introduce Joint Self-Improvement (JSI), a framework for sample-efficient online and offline molecular optimization. JSI combines **(i) a joint generative-predictive model** trained via a joint likelihood-based loss, which aligns molecule generation and surrogate modeling, and **(ii) inference-time self-improvement**, which iteratively biases the generative component of the joint model toward higher-scoring molecules using direct objective evaluations in the online setting and the predictive component in the offline setting. Experiments across docking score optimization, in both online and offline settings, as well as antimicrobial peptide optimization, demonstrate that JSI outperforms state-of-the-art methods under limited evaluation budgets.

We study stochastic linear bandits with a linear safety constraint that depends on an unknown parameter, requiring every chosen action to be safe at every round with high probability, even though the safe decision set is initially unknown. Prior work achieves $\widetilde{O}(\sqrt{T})$ regret when the safety gap, i.e., the constraint slack at the optimal action, is strictly positive and known to the learner. However, only $\widetilde{O}(T^{2/3})$ regret is established in two distinct cases: when the gap is zero, and when the gap is positive but unknown. This raises two natural questions: is the $\widetilde{O}(T^{2/3})$ bound tight in the zero-gap case, and is knowledge of the gap necessary for $\widetilde{O}(\sqrt{T})$ regret when the gap is positive? We answer both. First, we establish an $\Omega(T^{2/3})$ lower bound for zero-gap instances, showing that the existing upper bound is tight in its dependence on the horizon. Second, we propose Epoch-SLUCB, an algorithm that attains $\widetilde{O}(\sqrt{T})$ regret whenever the safety gap is positive, without requiring its value to be known. We also provide numerical simulations to demonstrate the performance of our algorithm.

Although the mechanics of eigenvalue bias of self-supervised learning (SSL) in linear networks are well-understood, they remain theoretically disconnected from empirical shortcut learning, offering little guidance or intuition. In this paper, we present a theoretical analysis of this shortcut learning phenomenon through the lens of \textit{extent bias} and \textit{amplitude bias}, two forms of \textit{eigenvalue bias}. By investigating the relations among extent bias, amplitude bias, and learning priorities in SSL, we demonstrate that SSL prioritizes features based on dimensionality (object to image ratio) and amplitude (backdoor attack intensity), not their semantic importance. Our analysis reveals how the eigenvalues of the feature cross-correlation matrix influence which features are learned earlier, providing insights into why models preferentially learn shortcut features over more generalizable features.

We present SS3D, a web-scale SfM-based self-supervision pretraining pipeline for feed-forward 3D estimation from monocular video. Our model jointly predicts depth, ego-motion, and intrinsics in a single forward pass and is trained/evaluated as a coherent end-to-end 3D estimator. To stabilize joint learning, we use an intrinsics-first two-stage schedule and a unified single-checkpoint evaluation protocol. Scaling SfM self-supervision to unconstrained web video is challenging due to weak multi-view observability and strong corpus heterogeneity; we address these with a multi-view signal proxy (MVS) used for filtering and curriculum sampling, and with expert training distilled into a single student. Pretraining on YouTube-8M (~ 100M frames after filtering) yields strong cross-domain zero-shot transfer and improved fine-tuning performance over prior self-supervised baselines. We release the pretrained checkpoint and code.

Stochastic Partial Differential Equations (SPDEs) driven by random noise play a central role in modeling physical processes with rough spatio-temporal dynamics, such as turbulence flows, superconductors, and quantum dynamics. Although machine learning (ML)-based surrogate models have shown promise for efficiently approximating such dynamics, progress remains limited by the lack of a unified benchmark with controlled data generation and comprehensive evaluation. This gap is particularly significant for singular SPDEs, for which benchmark datasets are largely unavailable and reliable simulation requires numerically delicate schemes based on renormalization. Moreover, subtle differences in data-generation procedures, such as noise approximation, basis choice, and the inclusion of renormalization, can significantly affect the resulting datasets and, consequently, model evaluation. We introduce SPDEBench, the first unified benchmark for ML-based SPDE learning. SPDEBench provides ready-to-use datasets for physically and mathematically significant SPDEs on 1-3D domains with periodic or Dirichlet boundary condition. Both regular and singular SPDEs are taken into consideration. SPDEBench also incorporates representative ML baselines in operator learning, together with 7 evaluation metrics, including Sobolev and distributional metrics beyond the standard $L^2$-error. Supported by SPDEBench, we conduct systematic evaluations of model accuracy, robustness, and out-of-distribution generalization under controlled data variations. Our numerical results show that SPDE-aware architectures generally achieve stronger performance than generic operator-learning baselines. These findings establish SPDEBench as a reproducible and extensible resource, paving pathway for principled benchmarking and architecture design for stochastic spatio-temporal dynamics.

We identify a theoretical incompatibility between 3D point cloud masked autoencoding and SE(3)-equivariant networks. We prove that standard masking triggers a topological collapse, effectively forcing the model to hallucinate orientation without a reference frame. To resolve this, we introduce SIEVE (Scalar Invariant Extraction Via Equivariance), an SE(3)-equivariant self-supervised framework that compresses point cloud geometry into invariant scalar embeddings. At its core is the spherical projection mask, which preserves global pose while obfuscating local semantics, sidestepping the obstruction by construction. Experiments confirm that SIEVE circumvents the predicted collapse where constant and noise masks fail. On downstream point cloud tasks, the resulting embeddings improve over coordinate-based baselines and hand-crafted geometric descriptors, with the largest gains on generalization to unseen shape categories.

Graph Neural Networks (GNNs) have achieved remarkable performance in a wide range of graph-related learning tasks. However, explaining their predictions remains a challenging problem, especially due to the mismatch between the graphs used during training and those encountered during explanation. Most existing methods optimize soft edge masks on weighted graphs to highlight important substructures, but these graphs differ from the unweighted graphs on which GNNs are trained. This distributional shift leads to unreliable gradients and degraded explanation quality, especially when generating small, sparse subgraphs. To address this issue, we propose explaining a robust surrogate whose explanations provide a faithful proxy for those of the original model. Specifically, we train this surrogate model through an iterative re-weighting strategy that alternates between identifying explanation subgraphs and adapting the model to the resulting weighted graph distribution, supporting stable explanation refinement while preserving the validity of the soft-mask relaxation. We evaluate our method on multiple benchmark datasets using different GNN backbones and explanation methods. Experimental results show that our method consistently improves explanation quality and can be flexibly integrated with different architectures.

Transformers have rapidly emerged as powerful surrogate models for learning solution operators for partial differential equations (PDEs). Standard attention tends to exhibit depth-wise representational bottlenecks across layers, with the role of depth remaining underexplored in modeling complex PDEs. In this paper, we rethink the role of depth by promoting it to an explicit computational dimension of attention kernel construction, rather than a passive architectural parameter. With this strategy, each attention block's native representation is enriched via a gated mixture of inter-layer differences, enabling information to be coupled and propagated across layers. The depth-wise hierarchy admits a theoretically motivated multi-kernel interpretation with weakly correlated kernels and improved generalization bounds. Beyond dense feature aggregation, our approach yields a more expressive form of depth-wise attention, mitigating spectral collapse, preserving interaction-scale diversity, and improving intra- and inter-layer route utilization. Extensive empirical evaluations demonstrate its broad compatibility across state-of-the-art solvers, presenting consistent performance gains on eight PDE benchmarks.

Model-assisted semi-supervised learning offers a powerful paradigm for enhancing the efficiency of statistical estimation and inference by leveraging black-box predictions on unlabeled data. However, the validity of these methods typically relies on the strict assumption that labeled and unlabeled populations share identical distributional characteristics. Consequently, state-of-the-art approaches, such as prediction-powered inference, become fragile when this assumption is violated. To address the fragility, we propose a robust framework for semi-supervised learning that remains reliable under distributional heterogeneity. By embedding a robust statistical calibrator into the prediction-rectification mechanism, the approach effectively reduces the bias arising from shifted or corrupted unlabeled samples. To maximize data utility, we introduce an adaptive cross-validation procedure to select the optimal calibrator, ensuring a reliable trade-off between statistical efficiency and robustness. Theoretical analysis confirms the consistency of the proposed estimator under mild conditions, while empirical results demonstrate its significant superiority over conventional baselines in heterogeneous environments.

Bayesian optimization (BO) is a widely used iterative black-box optimization method that utilizes Gaussian process (GP) surrogate models. In practice, BO is typically terminated after a fixed evaluation budget is exhausted, which can incur unnecessary cost and provides no optimality guarantee on solution quality. Recent research in developing a practical stopping criterion has made empirical progress, yet a theoretically sound stopping criterion remains a work in progress. In this work, we present provably tighter instantaneous regret bounds for GP upper confidence bound (GP-UCB) at any given iteration. Then, we propose stopping criteria for GP-UCB based on this tighter bound that ensures an $\epsilon$-optimal solution with high probability $1-\delta$ upon termination. Numerical experiments are performed to validate and demonstrate the effectiveness and efficiency of our stopping criteria.

Tissue graph counterfactuals ask how a cell's expression would change under altered spatial contexts. Such queries are central to predicting cell behavior in tissues, but lack a unified definition, with existing methods targeting specific intervention types or treating cells as i.i.d. In this work, we first formalize tissue graph counterfactuals as a class of spatial interventions that either rewire connections between cells (edge perturbation) or modify the expression of their neighbors (node perturbation). We then introduce Cellina, a modeling framework that uses supervised disentanglement to decompose a cell's intrinsic state from its spatial context, using the latter as a conditioning input for counterfactual predictions. Across benchmarks spanning 2.5 million spatially-resolved cells in colorectal cancer and mouse brain, Cellina outperforms spatially-informed and non-spatial competitors in counterfactual predictions, disentanglement, and scalability. Additionally, we show that Cellina reveals biologically distinct cancer subdomains in an unsupervised manner and enables targeted neighbor perturbation simulations.

The widespread deployment of large language models (LLMs) has made reliable detection of machine-generated text increasingly critical. Recent curvature-based detectors introduce perturbations to candidate text and compute curvature as the log probability difference between original and perturbed variants using advanced surrogate models. However, such curvature measurements only capture weak discrepancies between machine-generated and human-written text. We propose $\textbf{Pref-DetectGPT}$, a training-free method that introduces preference-aware curvature measurement by leveraging the implicit preference capabilities of preference-optimized surrogate models. Specifically, we construct an implicit reward model from the preference-optimized policy to score both original and perturbed text, and redefine curvature as their normalized deviation, which serves as a significantly stronger signal for distinguishing machine-generated text from human-written text. Empirical evaluations across multiple public benchmark datasets demonstrate that Pref-DetectGPT achieves state-of-the-art detection performance with relative improvements of 3.49\%, 3.13\%, and 10.66\% in AUROC, AUPR, and TPR5\%, while exhibiting strong robustness against various adversarial attacks and input lengths.

The validity of statistical inference depends critically on how data are collected.When data gathered through active data collection (ADC) are reused for a post-hoc inferential task, conventional inference can fail because the sampling process is adaptively biased toward regions favored by the collection strategy. This issue is especially pronounced in black-box optimization, where sequential model-based optimization (SMBO) methods such as the tree-structured Parzen estimator (TPE) and Gaussian process upper confidence bound (GP-UCB) preferentially concentrate evaluations in promising regions. We study statistical inference on actively collected data when the inferential target is constructed in a data-dependent manner after data collection. To enable valid inference in this setting, we propose post-ADC inference, a framework that accounts for the biases arising from both the active data collection process and the subsequent data-driven target construction. Our method builds on selective inference and provides valid $p$-values and confidence intervals that correct for both sources of bias. The framework applies to a broad class of ADC processes by imposing only assumptions on the observation noise, without requiring any assumptions on the underlying black-box function or the surrogate model used by the SMBO algorithm. Empirical results also show that post-ADC inference provides valid inference for data collected by GP-UCB and TPE.

Tokens are discrete representations that allow modern deep learning to scale by transforming high-dimensional data into sequences that can be efficiently learned, generated, and generalized to new tasks. While foundational for image and video generation, the application of tokens to physical simulation remains nascent. Because existing tokenizers are designed for the perceptual requirements of natural images, they struggle with scientific data, which exhibits large dynamic ranges and requires exact preservation of physical and spectral properties. In this work, we investigate the performance of a suite of image tokenizers across metrics designed to measure PDE fidelity. Observing that these baselines struggle to simultaneously capture fine geometric details and precise physical magnitudes, we propose Phaedra, a novel tokenizer inspired by classical shape-gain quantization and the paradigm of basis functions coupled with continuous coefficients. Phaedra acts as a highly effective nonlinear compression algorithm, massively reducing dataset footprints while maintaining physical fidelity. We demonstrate that Phaedra consistently improves reconstruction across diverse PDE datasets, generalizes robustly to unseen PDE types and real-world Earth observation data, and provides immediate accuracy gains in initial downstream operator learning and masked autoencoding tasks.

Scientific machine learning has opened new avenues for solving parameterized partial differential equations (PDEs), enabling models to learn a family of PDEs and generalize to unseen instances. In this context, data-driven operator learning methods typically require large training datasets, while physics-informed neural networks (PINNs) suffer from difficult optimization and limited generalization, especially for nonlinear PDEs. We propose Newton-PINet, a physics-informed network enhanced by Newton linearization, offering an effective meta-learning framework for nonlinear PDEs. Newton-PINet (i) employs a physics-informed multilayer network with skip connections, where the output-layer weights are solved by least squares; (ii) adopts a two-stage learning strategy that first leverages gradient-based training to learn robust representations from the available training tasks, and then performs gradient-free fine-tuning on the output layer for fast task-specific generalization; and (iii) incorporates a Newton linearization method to speed up the least-squares iteration for nonlinear PDE problems. On a challenging nonlinear reaction-diffusion benchmark, Newton-PINet achieves up to three orders of magnitude lower relative error than recent neural solvers, while using 16× fewer training tasks and over an order of magnitude less training time (under 5 minutes versus several hours). This work advances the meta-learning of PINNs toward data-efficient, fast, and generalizable physics solvers. The datasets and code are provided in the supplementary material.

In the context of computational materials science, analytical homogenization theories, such as Strong Contrast Expansion (SCE), develop PDE-induced power expansions that map microstructural statistics of material samples to their macroscopic effective properties. However, low-order truncations of such expansions for computational feasibility often trade off prediction accuracy, especially when high-order correlations, finite-resolution effects, or strong contrast regimes become important. While learned residual surrogates, e.g., neural operators, can alleviate this tradeoff, they do not ensure reliable inference of structure-property sensitivities, hampering downstream material design tasks. To this end, we propose Neural-Corrected Operator (NCO) that learns a correction directly to the analytical PDE kernel to compensate for the low-order truncation, and show that NCO intrinsically bounds sensitivity inferences. We evaluate NCO on structure-property prediction and inverse-design tasks for heterogeneous bi-phase composite materials governed by linear second-order PDEs. NCO improves the accuracy of low-order SCE models for structure-property prediction and produces sensitivities that facilitate more effective microstructure design optimization than output-level residual baselines.

Partial differential equations (PDEs) are central to modeling physical and engineering systems, but repeatedly solving parametric PDEs remains computationally expensive. Operator learning enables fast surrogate inference, yet typically requires large input–output paired datasets generated by costly high-fidelity PDE solvers. Unsupervised operator learning frameworks alleviate data dependency but remain hindered by computational bottlenecks. To address this, we propose Neural Variational Quantum Linear Solver (NVQLS), the first hybrid quantum–classical operator learning framework leveraging the Legendre-Galerkin weak formulation. We critically resolve the sign ambiguity in VQLS energy minimization, preventing erroneous solution representations. Additionally, we introduce a neural embedding, a novel encoding scheme to map varying forcings and PDE coefficients into parameterized quantum circuit representations. These structural innovations provide theoretical computational complexity advantages under efficient state preparation schemes, while achieving superior accuracy compared to a representative classical baseline. Validations on 1D and 2D parametric PDEs under diverse boundary conditions demonstrate NVQLS's capability to simultaneously process varying inputs, offering a scalable unsupervised approach to quantum-enhanced operator learning.

Compressible multiphase flows involving shocks and material interfaces arise in applications such as bubble collapse and droplet breakup, where strong nonlinear interactions produce complex interface deformation, mixing, and multiscale dynamics. Developing reliable machine learning surrogates for these flows remains challenging due to the simultaneous presence of compressibility, sharp discontinuities, and multiphase effects. In this work, we introduce the first large-scale benchmark specifically designed for shock-driven compressible multiphase flows, comprising 2.4 TB of high-fidelity 2D and 3D datasets featuring shock-induced bubble collapse and droplet breakup. We evaluate diverse surrogate model families on our benchmarking framework: Neptuna, including convolutional, spectral, transformer-based, and pre-trained PDE foundation models. Beyond standard MSE training, we investigate composite losses combining MSE with Sobolev, interface-aware, and structure-aware terms, together with adaptive loss balancing using SoftAdapt and GradNorm. Evaluation includes pointwise, spectral, feature-focused, structural, and physics-informed metrics. Results show that no single model performs best across all datasets and metrics, while composite losses significantly improve interface preservation and spectral fidelity. Among adaptive weighting strategies, SoftAdapt provides the most consistent improvements with almost no overhead compared to MSE-only training.