NeurIPS 2026 Papers

Audio--visual joint representation learning under Cross-Modal Generalization (CMG) aims to transfer knowledge from a labeled source modality to an unlabeled target modality through a unified discrete representation space. Existing symmetric frameworks often suffer from information allocation ambiguity, where the absence of structural inductive bias leads to semantic--specific leakage across modalities. We propose Asymmetric Hierarchical Anchoring (AHA), which enforces directional information allocation by designating a structured semantic anchor within a shared hierarchy. In our instantiation, we exploit the hierarchical discrete representations induced by audio Residual Vector Quantization (RVQ) to guide video feature distillation into a shared semantic space. To ensure representational purity, we replace fragile mutual information estimators with a GRL-based adversarial decoupler that explicitly suppresses semantic leakage in modality-specific branches, and introduce Local Sliding Alignment (LSA) to encourage fine-grained temporal alignment across modalities. Extensive experiments on AVE and AVVP benchmarks demonstrate that AHA consistently outperforms symmetric baselines in cross-modal transfer. Additional analyses on talking-face disentanglement experiment further validate that the learned representations exhibit improved semantic consistency and disentanglement, indicating the broader applicability of the proposed framework.

Matrix-vector products (MVPs) are a key primitive in numerical linear algebra and machine learning. However, the naive quadratic running time for exact computation is prohibitive for large matrices, motivating approximate methods. In this paper, we study approximate MVPs under a natural ``lightness'' assumption, which bounds the total $\ell_1$-mass of a $n \times n$ input matrix $A$ by $\gamma n$. For general matrices, we give an algorithm for approximating $Ax$ up to additive $\epsilon \|x\|_2$ error in $O(\gamma n^{1.5}/\epsilon)$ query time and polynomial preprocessing. We extend this algorithm to kernel matrices by establishing a black-box reduction to Kernel Density Estimation data structures and analyzing a noisy entry sampling scheme. For kernel matrices, our algorithm does not require any preprocessing and improves the best-known running times for Gaussian kernel matrices of [Indyk, Kapralov, Sheth, Wagner; ICLR `25] by polynomial factors in $n$ and $1/\epsilon$, and also provides the first algorithms leveraging the lightness assumption for other kernel functions as well.

Key--value (KV) cache quantization is widely used to reduce Large Language Model (LLM) inference memory, yet existing evaluations solely focus on measuring perplexity and accuracy without assessing the safety impact. In this study, we explore alignment preservation under KV cache quantization. Across eleven instruction-tuned models (3.8B--72B) and five benchmarks (1,894 prompts), we find that low-bit quantization can silently destroy safety alignment (Mistral-7B loses 15.2\% of its refusals at only $1.03\times$ perplexity, and no universal safe bit-width exists), with sharp model-specific phase transitions invisible to standard metrics. We identify that the root cause is geometric: safety features occupy a low-dimensional activation subspace $10^2$-$10^3\times$ more vulnerable to quantization noise than the full representation space perplexity averages over. Inspired by this observation, we propose **Per-Channel Reduction** (PCR), a diagnostic that classifies each model into one of three mechanistic failure modes: (i) *outlier-crushes-safety*, where safety lives in non-outlier channels collaterally damaged by outlier-driven scale factors; (ii) *outlier-as-safety*, where safety overlaps outlier channels and finer granularity cannot rescue it; (iii) *multi-layer dilution*, where safety is distributed across many layers and per-layer fixes fail. PCR predicts the correct mitigation direction on all nine primary models and one held-out model from an independent family (20 calibration prompts). PCR generalizes across unseen prompts, models, and production quantizers (KIVI: up to 97.2\% recovery), succeeding where attention-based allocation methods fail. The resulting training-free protocol (${\sim}35$ GPU-minutes) recovers up to 97\% of lost alignment at minimal memory overhead, addressing vulnerabilities confirmed in production vLLM serving with FP8 KV cache on NVIDIA GPUs.

Open-Vocabulary Multimodal Emotion Recognition (OV-MER) aims to predict emotions without being constrained by predefined label spaces, thereby enabling fine-grained emotion understanding. Unlike traditional discriminative methods, OV-MER leverages generative models to capture the full spectrum of emotions and employs emotion wheels (EWs) for metric calculation. Previous approaches primarily rely on token-level loss during training. However, this objective is misaligned with the metrics used in OV-MER, and these metrics cannot be directly optimized via gradient backpropagation. To address this limitation, we turn our attention to reinforcement learning, as this strategy can optimize non-differentiable objectives. We term this framework **AffectGPT-RL**. Furthermore, we conduct extensive experiments to elucidate the role of reinforcement learning in this task, revealing the necessity of the reasoning process, the impact of different rewards, and the generalizability to other emotion tasks such as sentiment analysis and basic emotion recognition. Experimental results demonstrate that AffectGPT-RL yields significant performance improvements on OV-MER. Beyond this task, we also achieve remarkable performance gains on basic emotion recognition, attaining state-of-the-art results on MER-UniBench. To the best of our knowledge, this is the pioneering work exploring the role of reinforcement learning in OV-MER, providing valuable guidance for subsequent researchers. Our code is provided in the supplementary material and will be released to facilitate future research.

Large multimodal models (LMMs) have advanced rapidly in perception and reasoning, yet it remains unclear whether they can discover visually grounded, physically feasible solutions in open-ended environments. We first introduce **MM-CreativityBench**, a benchmark for affordance-grounded creative tool use, where models must inspect scenes, entities, and parts to identify non-obvious object uses grounded in visual evidence. Our evaluation shows that current LMMs often fail to sustain grounded exploration: they overlook relevant entities, under-examine critical parts, or hallucinate unsupported attributes. To address these failures, we propose **affordance-grounded alignment**, framing creative tool use as a preference learning problem. Using Direct Preference Optimization and supervision from an affordance knowledge base, we train models to favor visually grounded attribute–affordance reasoning over hallucinated alternatives while improving exploration efficiency. Our results yield consistent gains in correct entity and part selection, and reduce hallucination and grounding errors. These findings position grounded creativity as a core capability for future multimodal agents: the ability to adapt to unfamiliar environments and solve problems beyond memorized patterns or surface-level plausibility, moving closer to real human-like intelligence.

Reliable prediction of material properties from atomistic structures requires machine learning models that respect SE(3) symmetry. Frame-based methods address this challenge by constructing equivariant coordinate systems that align SE(3)-equivalent structures into unified representations. While attractive for their flexibility and efficiency, existing frame-based methods face two major limitations: a single frame type is often insufficient for heterogeneous atomic environments, and frame constructions can become unstable near highly symmetric or degenerate configurations. To address these issues, we propose the Multi-Frame Adaptive Network (MFAN), which leverages multiple frame types and introduces a local adaptive mechanism to combine them according to atomic environments, enabling different geometric references across atoms and complementary local-global information for each atom. Building on this multi-frame architecture, we further incorporate a frame-quality-aware weighting scheme that downweights unreliable frames before degeneration, thereby improving the continuity of the resulting representation. Experiments on crystal property prediction benchmarks demonstrate the leading performance of MFAN, with consistent gains from adaptive multi-frame learning. Additional force prediction experiments show improved robustness in continuity-sensitive settings.

Large Language Models (LLMs) deployed as AI agents frequently exhibit a task-completion bias, executing hallucinated, undesired actions to force a resolution rather than expressing uncertainty. Existing detection methods fail to provide actionable, real-time correction as they either do not localize the hallucinations or incur prohibitive inference latency. We introduce the Latent Critic, a lightweight low-rank adapter (LoRA) that operates concurrently with a frozen base LLM's generation to actively restructure the transformer's residual stream---amplifying epistemic uncertainty signals and translating them into localized, natural language feedback within a single sequence. By refining the base model's native uncertainty signals, this manipulation of the latent space enables highly reliable, granular detection without the overhead of secondary inference loops. Mechanistic analysis via activation patching and layer-wise probing shows that this rank-invariant behavior restructures pre-existing uncertainty geometry into a linearly separable representation. Using tool-calling as an instantiation of granular hallucinations, we validate the detection and downstream improvements enabled by the Latent Critic architecture across Qwen and Llama-based models. Demonstrating superior real-time efficacy, our approach significantly outperforms equivalent-scale external detectors and internal probes in isolating hallucinations (0.870 vs. 0.695 F1), achieving >80% accuracy in localization (e.g., ungrounded: date). When deployed in a closed-loop ReAct environment, the Critic acts as a zero-latency guardrail, intercepting hallucinations before execution to prevent undesired actions while simultaneously enabling efficient agent self-correction.

Diffusion Language Models (DLMs) exhibit strong parallel decoding capabilities by denoising multiple tokens in a single generation step. However, this parallelism comes with substantial computational overhead, as each step requires interactions with all suffix tokens. Existing methods typically reduce this cost by retaining only a local suffix window as a substitute for the full suffix. Despite their effectiveness, these methods overlook the structural heterogeneity across suffix regions and re-initialize suffix tokens with identical representations at each timestep. To this end, we propose a structured suffix modeling method for efficient DLM inference. Specifically, we divide the suffix into three regions, i.e., the local, middle, and tail regions, and retain different numbers of suffix tokens in each region according to their structural roles. Moreover, we incorporate the decoding results from the previous step into the suffix token representations at the current step, allowing them to carry evolving denoising information across generation steps. Notably, our method is training-free and orthogonal to several existing acceleration techniques, such as parallel decoding strategies and KV cache. Empirical results across multiple benchmarks on three DLMs demonstrate that our method can further accelerate DLM inference and, in most cases, also improve task performance. In particular, in long-sequence inference, our method achieves up to a \(72.16\times\) speedup when combined with other acceleration techniques.

Audio-video (AV) editing aims to modify audio and video content according to a target prompt. Unlike single-modality editing, AV editing requires models to infer a modality-selective edit scope from the prompt alone: determining not only what should change, but also which modality should be preserved. Faithfully evaluating such models therefore requires both (i) benchmarks that span diverse edit types and modality categories, and (ii) evaluation that is itself modality-aware and sample-specific. However, existing AV editing benchmarks provide limited coverage of edit types and modality combinations, while current evaluation systems are often modality-blind and sample-agnostic, making it difficult to assess whether models faithfully preserve the unintended modality. To address these gaps, we introduce AVENUE, Audio-Video EditiNg Understanding and Evaluation, comprising two contributions: (1) a benchmark of 1,291 source clips and 7,957 editing instructions across audio-targeted, video-targeted, and AV-coupled edit types, curated and human-verified from VGGSound; and (2) a sample-specific, modality-aware evaluation framework that specifies, for each sample, both the intended change and the content that must remain intact. We evaluate representative AV editing models spanning three editing paradigms — joint, sequential, and separate — providing the first systematic analysis of modality-selectivity across paradigms. Our findings reveal a fundamental open challenge: when editing one modality, existing models frequently induce unintended changes in the other, regardless of paradigm. AVENUE provides a benchmark and modality-aware evaluation framework to drive progress toward more controllable AV editing models.

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.

We present UniALM, a unified audio foundation model built on FactorCodec, a purely discrete tokenizer that factorizes audio into two role-separated representations. Analysis tokens are optimized to retain language-aligned, text-expressible information that can be decoded by a text LLM head into grounded natural-language analyses, while reconstruction tokens preserve the information required for waveform synthesis and are used exclusively for audio decoding. This factorization yields understanding performance competitive with continuous Whisper features on audio understanding tasks, while reducing the perplexity of reconstruction-token modeling for generation. UniALM further adopts functional layer specialization, partitioning the backbone into audio-understanding, cross-modal, and audio-generation experts. We train the model with a four-stage recipe on 100B text tokens and 60B audio tokens, together with a composed audio sequence construction strategy for unified multi-task pre-training. At 3B parameters, UniALM is competitive with strong 7B unified baselines on in-domain tasks and exhibits non-trivial \emph{compositional generalization} to unseen tasks under few-shot and zero-shot evaluation. Unlike prior unified systems that rely on hybrid continuous-discrete inputs or do not support generation beyond speech, UniALM provides a purely discrete interface for both understanding and generation across speech, sound, and music.

We study connections between the sample cost of replicability, which requires an algorithm to produce consistent outputs in different runs, and the sample complexity in the high success probability regime for distribution testing algorithms. Specifically, we consider a stronger notion of replicability, which we term as strong replicability, and show that any $\rho$-strongly-replicable testing algorithm can be converted in a blackbox manner to a tester with at most $\exp(-\tilde{\Omega}(\rho^{-2}))$ failure probability under the same sample budget. Our conversion is optimal for many natural testers. As applications of our conversion theorem, we obtain tight sample lower bounds for strongly replicable testers for coin bias and closeness testing.