Expert Certification: On Convolutions, Intrinsic Dimension, and Diffusion Models
Kin Kwan Leung, Rasa Hosseinzadeh, Gabriel Loaiza-Ganem
https://openreview.net/forum?id=xSzBf1te4s
---
Accepted papers
===============
Title: Teaching Diffusion Models to Ground Alpha Matte
Authors: Tianyi Xiang, Weiying Zheng, Yutao Jiang, Tingrui Shen, Hewei Yu, Yangyang Xu, Shengfeng He
Abstract: The power of visual language models is showcased in visual understanding tasks, where language-guided models achieve impressive flexibility and precision. In this paper, we extend this capability to the challenging domain of image matting by framing it as a soft grounding problem, enabling a single diffusion model to handle diverse objects, textures, and transparencies, all directed by descriptive text prompts. Our method teaches the diffusion model to ground alpha mattes by guiding it through a process of instance-level localization and transparency estimation. First, we introduce an intermediate objective that trains the model to accurately localize semantic components of the matte based on natural language cues, establishing a robust spatial foundation. Building on this, the model progressively refines its transparency estimation abilities, using the learned semantic structure as a prior to enhance the precision of alpha matte predictions. By treating spatial localization and transparency estimation as distinct learning objectives, our approach allows the model to fully leverage the semantic depth of diffusion models, removing the need for rigid visual priors. Extensive experiments highlight our model’s adaptability, precision, and computational efficiency, setting a new benchmark for flexible, text-driven image matting solutions.
URL: https://openreview.net/forum?id=2gNy9Yeg8J
---
Title: On Convolutions, Intrinsic Dimension, and Diffusion Models
Authors: Kin Kwan Leung, Rasa Hosseinzadeh, Gabriel Loaiza-Ganem
Abstract: The manifold hypothesis asserts that data of interest in high-dimensional ambient spaces, such as image data, lies on unknown low-dimensional submanifolds. Diffusion models (DMs) -- which operate by convolving data with progressively larger amounts of Gaussian noise and then learning to revert this process -- have risen to prominence as the most performant generative models, and are known to be able to learn distributions with low-dimensional support. For a given datum in one of these submanifolds, we should thus intuitively expect DMs to have implicitly learned its corresponding local intrinsic dimension (LID), i.e. the dimension of the submanifold it belongs to. Kamkari et al. (2024b) recently showed that this is indeed the case by linking this LID to the rate of change of the log marginal densities of the DM with respect to the amount of added noise, resulting in an LID estimator known as FLIPD. LID estimators such as FLIPD have a plethora of uses, among others they quantify the complexity of a given datum, and can be used to detect outliers, adversarial examples and AI-generated text. FLIPD achieves state-of-the-art performance at LID estimation, yet its theoretical underpinnings are incomplete since Kamkari et al. (2024b) only proved its correctness under the highly unrealistic assumption of affine submanifolds. In this work we bridge this gap by formally proving the correctness of FLIPD under realistic assumptions. Additionally, we show that an analogous result holds when Gaussian convolutions are replaced with uniform ones, and discuss the relevance of this result.
URL: https://openreview.net/forum?id=xSzBf1te4s
---
Title: Equivalent Linear Mappings of Large Language Models
Authors: James Robert Golden
Abstract: Despite significant progress in transformer interpretability, an understanding of the computational mechanisms of large language models (LLMs) remains a fundamental challenge. Many approaches interpret a network's hidden representations but remain agnostic about how those representations are generated. We address this by mapping LLM inference for a given input sequence to an equivalent and interpretable linear system which reconstructs the predicted output embedding with relative error below $10^{-13}$ at double floating-point precision, requiring no additional model training. We exploit a property of transformer decoders wherein every operation (gated activations, attention, and normalization) can be expressed as $A(x) \cdot x$, where $A(x)$ represents an input-dependent linear transform and $x$ preserves the linear pathway. To expose this linear structure, we strategically detach components of the gradient computation with respect to an input sequence, freezing the $A(x)$ terms at their values computed during inference, such that the Jacobian yields an equivalent linear mapping. This ``detached’’ Jacobian of the model reconstructs the output with one linear operator per input token, which is shown for Qwen 3, Gemma 3 and Llama 3, up to Qwen 3 14B. These linear representations demonstrate that LLMs operate in extremely low-dimensional subspaces where the singular vectors can be decoded to interpretable semantic concepts. The computation for each intermediate output also has a linear equivalent, and we examine how the linear representations of individual layers and their attention and multilayer perceptron modules build predictions, and use these as steering operators to insert semantic concepts into unrelated text. Despite their expressive power and global nonlinearity, modern LLMs can be interpreted through equivalent linear representations that reveal low-dimensional semantic structures in the next-token prediction process. Code is available at https://github.com/jamesgolden1/equivalent-linear-LLMs/.
URL: https://openreview.net/forum?id=oDWbJsIuEp
---
Title: Where are we with calibration under dataset shift in image classification?
Authors: Mélanie Roschewitz, Raghav Mehta, Fabio De Sousa Ribeiro, Ben Glocker
Abstract: We conduct an extensive study on the state of calibration under real-world dataset shift for image classification. Our work provides important insights on the choice of post-hoc and in-training calibration techniques, and yields practical guidelines for all practitioners interested in robust calibration under shift. We compare various post-hoc calibration methods, and their interactions with common in-training calibration strategies (e.g., label smoothing), across a wide range of natural shifts, on eight different classification tasks across several imaging domains. We find that: (i) simultaneously applying entropy regularisation and label smoothing yield the best calibrated raw probabilities under dataset shift, (ii) post-hoc calibrators exposed to a small amount of semantic out-of-distribution data (unrelated to the task) are most robust under shift, (iii) recent calibration methods specifically aimed at increasing calibration under shifts do not necessarily offer significant improvements over simpler post-hoc calibration methods, (iv) improving calibration under shifts often comes at the cost of worsening in-distribution calibration. Importantly, these findings hold for randomly initialised classifiers, as well as for those finetuned from foundation models, the latter being consistently better calibrated compared to models trained from scratch. Finally, we conduct an in-depth analysis of ensembling effects, finding that (i) applying calibration prior to ensembling (instead of after) is more effective for calibration under shifts, (ii) for ensembles, OOD exposure deteriorates the ID-shifted calibration trade-off, (iii) ensembling remains one of the most effective methods to improve calibration robustness and, combined with finetuning from foundation models, yields best calibration results overall.
URL: https://openreview.net/forum?id=1NYKXlRU2H
---
Title: Diversity-Enhanced and Classification-Aware Prompt Learning for Few-Shot Learning via Stable Diffusion
Authors: Gaoqin Chang, Jun Shu, Xiang Yuan, Deyu Meng
Abstract: Recent text-to-image generative models have exhibited an impressive ability to generate fairly realistic images from some text prompts. In this work, we explore to leverage off-the-shelf text-to-image generative models to train non-specific downstream few-shot classification model architectures using synthetic dataset to classify real images. Current approaches use hand-crafted or model-generated text prompts of text-to-image generative models to generate desired synthetic images, however, they have limited capability of generating diverse images. Especially, their synthetic datasets have relatively limited relevance to the downstream classification tasks. This makes them fairly hard to guarantee training models from synthetic images are efficient in practice. To address this issue, we propose a method capable of adaptively learning proper text prompts for the off-the-shelf diffusion model to generate diverse and classification-aware synthetic images. Our approach shows consistently improvements in various classification datasets, with results comparable to existing prompt designing methods. We find that replacing data generation strategy of existing zero/few-shot methods with proposed method could consistently improve downstream classification performance across different network architectures, demonstrating its model-agnostic potential for few-shot learning. This makes it possible to train an efficient downstream few-shot learning model from synthetic images generated by proposed method for real problems.
URL: https://openreview.net/forum?id=4CfliohyqK
---
Title: Understanding Self-supervised Contrastive Learning through Supervised Objectives
Authors: Byeongchan Lee
Abstract: Self-supervised representation learning has achieved impressive empirical success, yet its theoretical understanding remains limited. In this work, we provide a theoretical perspective by formulating self-supervised representation learning as an approximation to supervised representation learning objectives. Based on this formulation, we derive a loss function closely related to popular contrastive losses such as InfoNCE, offering insight into their underlying principles. Our derivation naturally introduces the concepts of prototype representation bias and a balanced contrastive loss, which help explain and improve the behavior of self-supervised learning algorithms. We further show how components of our theoretical framework correspond to established practices in contrastive learning. Finally, we empirically validate the effect of balancing positive and negative pair interactions. All theoretical proofs are provided in the appendix, and our code is included in the supplementary material.
URL: https://openreview.net/forum?id=cmE97KX2XM
---
Title: Is isotropy a good proxy for generalization in time series forecasting with transformers?
Authors: Rashed Shelim, Shengzhe Xu, Walid Saad, Naren Ramakrishnan
Abstract: Vector representations of contextual embeddings learned by transformer-based models have been shown to be effective even for downstream tasks in \emph{numerical domains} such as time series forecasting. Their success in capturing long-range dependencies and contextual semantics has led to broad adoption across architectures. But at the same time, there is little theoretical understanding of when transformers, both autoregressive and non-autoregressive, generalize well to forecasting tasks. This paper addresses this gap through an analysis of isotropy in contextual embedding space. Specifically, we study a log-linear model as a simplified abstraction for studying hidden representations in transformer-based models. In this formulation, time series embeddings are mapped to predictive outputs through a softmax layer, providing a tractable lens for analyzing generalization. We show that state-of-the-art performance requires embeddings to possess a structure that accounts for the shift-invariance of the softmax function. By examining the gradient structure of self-attention, we demonstrate how isotropy preserves representation structure, resolves the shift-invariance problem, and provides insights into model reliability and generalization. Experiments across $22$ different numerical datasets and $5$ different transformer-based models show that data characteristics and architectural choices significantly affect isotropy, which in turn directly influences forecasting performance. This establishes isotropy as a theoretically grounded and empirically validated indicator of generalization and reliability in time series forecasting. The code for the isotropy analysis and all data are publicly available.
URL: https://openreview.net/forum?id=iUtDYVQzFq
---
New submissions
===============
Title: Rethinking Mixture-of-Agents: Is Mixing Different Large Language Models Beneficial?
Abstract: Ensembling outputs from diverse sources is a straightforward yet effective approach to boost performance. Mixture-of-Agents (MoA) is one such popular ensemble method that aggregates outputs from multiple \emph{different} Large Language Models (LLMs). This paper raises the question in the context of language models: is mixing different LLMs truly beneficial?
We propose Self-MoA --- an ensemble method that aggregates outputs from only the \emph{single} top-performing LLM. Our extensive experiments reveal that, surprisingly, Self-MoA outperforms standard MoA that mixes different LLMs in a large number of scenarios: Self-MoA achieves $6.6\%$ improvement over MoA on the AlpacaEval 2.0 benchmark, and an average of $3.8\%$ improvement across various benchmarks, including MMLU, CRUX, and MATH. Applying Self-MoA to one of the top-ranking models in AlpacaEval 2.0 directly achieves the new state-of-the-art performance on the leaderboard. To understand the effectiveness of Self-MoA, we systematically investigate the trade-off between diversity and quality of outputs under various MoA settings. We confirm that the MoA performance is rather sensitive to the quality, and mixing different LLMs often lowers the average quality of the models. To complement the study, we identify the scenarios where mixing different LLMs could be helpful. This paper further introduces a sequential version of Self-MoA, that is capable of aggregating a large number of LLM outputs on-the-fly over multiple rounds, and is as effective as aggregating all outputs at once.
URL: https://openreview.net/forum?id=K6WwK8URlV
---
Title: BalancedDPO: Adaptive Multi-Metric Alignment
Abstract: Diffusion models have achieved remarkable progress in text-to-image generation, yet aligning them with human preference remains challenging due to the presence of multiple, sometimes conflicting, evaluation metrics (e.g., semantic consistency, aesthetics, and human preference scores). Existing alignment methods typically optimize for a single metric or rely on scalar- ized reward aggregation, which can bias the model toward specific evaluation criteria. To address this challenge, we propose BalancedDPO, a framework that achieves multi-metric preference alignment within the Direct Preference Optimization (DPO) paradigm. Unlike prior DPO variants that rely on a single metric, BalancedDPO introduces a majority-vote consensus over multiple preference scorers and integrates it directly into the DPO training loop with dynamic reference model updates. This consensus-based formulation avoids reward- scale conflicts and ensures more stable gradient directions across heterogeneous metrics. Experiments on Pick-a-Pic, PartiPrompt, and HPD datasets demonstrate that Balanced- DPO consistently improves preference win rates over the baselines across Stable Diffusion 1.5, Stable Diffusion 2.1 and SDXL backbones. Comprehensive ablations further validate the benefits of majority-vote aggregation and dynamic reference updating, highlighting the method’s robustness and generalizability across diverse alignment settings.
URL: https://openreview.net/forum?id=8HRID5VLQw
---
Title: Mollifier Layers: Enabling Efficient High-Order Derivatives in Inverse PDE Learning
Abstract: Parameter estimation in inverse problems involving partial differential equations (PDEs) underpins modeling across scientific disciplines, especially when parameters vary in space or time. Physics-informed Machine Learning (PhiML) integrates PDE constraints into deep learning, but prevailing approaches depend on recursive automatic differentiation (autodiff), which produces inaccurate high-order derivatives, inflates memory usage, and underperforms in noisy settings. We propose Mollifier Layers, a lightweight, architecture-agnostic module that replaces autodiff with convolutional operations using analytically defined mollifiers. This reframing of derivative computation as smoothing integration enables efficient, noise-robust estimation of high-order derivatives directly from network outputs. Mollifier Layers attach at the output layer and require no architectural modifications. We compare them with three distinct architectures and benchmark performance across first-, second-, and fourth-order PDEs—including Langevin dynamics, heat diffusion, and reaction-diffusion systems—observing significant improvements in memory efficiency, training time and accuracy for parameter recovery across tasks. To demonstrate practical relevance, we apply Mollifier Layers to infer spatially varying epigenetic reaction rates from super-resolution chromatin imaging data—a real-world inverse problem with biomedical significance. Our results establish Mollifier Layers as an efficient and scalable tool for physics-constrained learning.
URL: https://openreview.net/forum?id=6mFVZSzyev
---
Title: Learning and Transferring Physical Models through Derivatives
Abstract: We propose Derivative Learning (DERL), a supervised approach that models physical systems by learning their partial derivatives. We also leverage DERL to build physical models incrementally, by designing a distillation protocol that effectively transfers knowledge from a pre-trained model to a student one. We provide theoretical guarantees that DERL can learn the true physical system, being consistent with the underlying physical laws, even when using empirical derivatives. DERL outperforms state-of-the-art methods in generalizing an ODE to unseen initial conditions and a parametric PDE to unseen parameters. We also design a method based on DERL to transfer physical knowledge across models by extending them to new portions of the physical domain and a new range of PDE parameters. We believe this is the first attempt at building physical models incrementally in multiple stages.
URL: https://openreview.net/forum?id=IbBCDDeDF7
---
Title: Probabilistic Pretraining for Improved Neural Regression
Abstract: While transfer learning has revolutionized computer vision and natural language processing, its application to probabilistic regression remains underexplored, particularly for tabular data. We introduce NIAQUE (Neural Interpretable Any-Quantile Estimation), a novel permutation-invariant architecture that enables effective transfer learning across diverse regression tasks. Through extensive experiments on 101 datasets, we demonstrate that pre-training NIAQUE on multiple datasets and fine-tuning on target datasets consistently outperforms both traditional tree-based models and transformer-based neural baseline. On real-world Kaggle competitions, NIAQUE achieves competitive performance against heavily hand-crafted and feature-engineered solutions and outperforms strong baselines such as TabPFN and TabDPT, while maintaining interpretability through its probabilistic framework. Our results establish NIAQUE as a robust and scalable approach for tabular regression, effectively bridging the gap between traditional methods and modern transfer learning.
URL: https://openreview.net/forum?id=F6BTATGXaf
---
Title: Instruction-Level Weight Shaping: A Framework for Self- Improving AI Agents
Abstract: Large language models (LLMs) excel at surface fluency yet remain structurally static after pre-training; new or evolving domain knowledge is typically bolted on via retrieval-augmented generation (RAG) or parameter fine-tuning. In practice, RAG often retrieves facts without integrating them logically, adds latency and engineering overhead. Free-form prompt injection and ad hoc prompt engineering are brittle, prone to context-window drift, and can conflict with pre-trained knowledge. Fine-tuning, while effective for specific domains, is resource-intensive and risks catastrophic forgetting.
We propose Instruction-Level Weight Shaping (ILWS), which treats curated system instructions as external, auditable pseudo-parameters updated post-session via reflection and user feedback. After each session an LLM-driven Reflection Engine inspects the conversation trace, diagnoses reasoning successes or failures, and proposes typed deltas $\Delta K=(\Delta S,\Delta U,\Delta T)$ over instructions, user preferences, and tools. Each delta is version-controlled, evaluated under a sliding-window analysis of 1-5 star ratings, automatically repaired on first failure, and rolled back on repeated failure. When the accumulated edit budget crosses a threshold, the agent compiles a rating-weighted synthetic dataset and distils matured instruction-space gains into parameters, converting prompt-space improvements into weight-space without downtime.
Empirically, ILWS makes explicit the low-rank shaping implicitly induced by context in transformer blocks and preserves governance while eliminating per-call retrieval. In enterprise support, ILWS raised throughput by 2.4--5.0$\times$ and cut audited hallucinations by $\sim$80% versus a frozen baseline. A real-world e-commerce platform PoC called "L0 Support" with 1M-token context achieved 4--5$\times$ gains in tickets/hour and an $\sim$80% reduction in time per ticket, with autonomous instruction updates and optional tool synthesis. Because ILWS operates at the instruction layer until a controlled distillation stage, it generalises to dynamic domains (legal, medical, engineering) requiring adaptive reasoning, tool creation, and low-latency deployment.
URL: https://openreview.net/forum?id=2unHBbaor7
---
Title: SpikingMamba: Towards Energy-Efficient Large Language Models via Knowledge Distillation from Mamba
Abstract: Large Language Models (LLMs) have achieved remarkable performance across tasks but remain energy-intensive due to dense matrix operations. Spiking neural networks (SNNs) improve energy efficiency by replacing dense matrix multiplications with sparse accumulations. Their sparse spike activity enables efficient LLMs deployment on edge devices. However, prior SNN-based LLMs often sacrifice performance for efficiency, and recovering accuracy typically requires full pretraining, which is costly and impractical. To address this, we propose SpikingMamba, an energy-efficient SNN-based LLMs distilled from Mamba that improves energy efficiency with minimal accuracy sacrifice. SpikingMamba integrates two key components: (a) TI-LIF, a ternary-integer spiking neuron that preserves semantic polarity through signed multi-level spike representations. (b) A training-exclusive Smoothed Gradient Compensation (SGC) path mitigating quantization loss while preserving spike-driven efficiency. We employ a single-stage distillation strategy to transfer the zero-shot ability of pretrained Mamba and further enhance it via reinforcement learning (RL). Experiments show that SpikingMamba-1.3B achieves a 4.76$\times$ energy benefit, with only a 4.78% zero-shot accuracy gap compared to the original Mamba, and achieves a further 2.55% accuracy improvement after RL.
URL: https://openreview.net/forum?id=uxb2jcCLxt
---
Title: Interpretable Traces, Unexpected Outcomes: Investigating the Disconnect in Trace-Based Knowledge Distillation
Abstract: Recent advances in reasoning-oriented Large Language Models (LLMs) have been driven by the introduction of Chain-of-Thought (CoT) traces, where models generate intermediate reasoning traces before producing an answer. These traces, as in DeepSeek R1, are not only used to guide model inference but also serve as supervision signals for Knowledge Distillation (KD) to improve smaller models. A prevailing but under-examined implicit assumption is that these CoT traces are both semantically correct and interpretable for the end-users. While there are reasons to believe that these intermediate tokens help improve solution accuracy, in this work, we question their validity (semantic correctness) and interpretability to the end user. To isolate the effect of trace semantics, we design experiments in the Question Answering (QA) domain using a rule-based problem decomposition method. This enables us to create Supervised Fine-Tuning (SFT) datasets for LLMs where - each QA problem is paired with either verifiably correct or incorrect CoT traces, while always providing the correct final solution. Trace correctness is then evaluated by checking the accuracy of every sub-step in decomposed reasoning chains. To assess end-user trace interpretability, we also finetune LLMs with three additional types of CoT traces: DeepSeek R1 traces, LLM-generated summaries of R1 traces, and LLM-generated post-hoc explanations of R1 traces. We further conduct a human-subject study with 100 participants asking them to rate the interpretability of each trace type on a standardized Likert scale. Our experiments reveal two key findings - (1) Correctness of CoT traces is not reliably correlated with the model’s generation of correct final answers: correct traces led to correct solutions only for 28% test-set problems while incorrect traces don't necessarily degrade solution accuracy. (2) In interpretability studies, fine-tuning on verbose DeepSeek R1 traces produced the best model performance but these traces were rated as least interpretable by users, scoring on average 3.39 for interpretability and 4.59 for cognitive load metrics on a 5-point Likert scale. In contrast, the decomposed traces that are judged significantly more interpretable don't lead to comparable solution accuracy. Together, these findings challenge the assumption in question suggesting that researchers and practitioners should decouple model supervision objectives from end-user-facing trace design.
URL: https://openreview.net/forum?id=4D1QEEmabF
---
Title: The Transformer Cookbook
Abstract: We present the transformer cookbook: a collection of techniques for directly encoding algorithms into a transformer's parameters. This work addresses the steep learning curve of such endeavors, a problem exacerbated by a fragmented literature where key results are scattered across numerous papers. In particular, we synthesize this disparate body of findings into a curated set of recipes that demonstrate how to implement everything from basic arithmetic in feed-forward layers to complex data routing via self-attention. Our mise en place of formulations is for both newcomers seeking an accessible entry point and experts in need of a systematic reference. This unified presentation of transformer constructions provides a foundation for future work spanning theoretical research in computational complexity to empirical investigations in architecture design and interpretability.
URL: https://openreview.net/forum?id=sPshCSvDrX
---
Title: There are no Champions in Long-Term Time Series Forecasting
Abstract: Recent advances in long-term time series forecasting have introduced numerous complex prediction models that consistently outperform previously published architectures.
However, this rapid progression raises concerns regarding inconsistent benchmarking and reporting practices, which may undermine the reliability of these comparisons.
Our position emphasizes the need to shift focus away from pursuing ever-more complex models and towards enhancing benchmarking practices through rigorous and standardized evaluation methods.
To support our claim, we first perform a broad, thorough, and reproducible evaluation of the top-performing models on the most popular benchmark by evaluating five models over 14 datasets encompassing 3,500+ trained networks for the hyperparameter (HP) searches.
Then, through a comprehensive analysis, we find that slight changes to experimental setups or current evaluation metrics drastically shift the common belief that newly published results are advancing the state of the art.
Our findings suggest the need for rigorous and standardized evaluation methods that enable more substantiated claims, including reproducible HP setups and statistical testing.
URL: https://openreview.net/forum?id=yO1JuBpTBB
---
Title: Shattering the Rings: Reproducibility and Vulnerability Analysis of the ZoDiac Watermarking Framework
Abstract: This paper presents a reproducibility study and robustness evaluation of the paper ‘Attack-
Resilient Image Watermarking Using Stable Diffusion’ by Zhang et al. (2024), which proposes
ZoDiac, a Stable Diffusion-based framework for attack-resilient image watermarking. While
successfully replicating the original method’s core claims—achieving >90% watermark de-
tection rate (WDR) against diffusion-based regeneration attacks and across MS-COCO,
DiffusionDB, and WikiArt datasets—we identify critical vulnerabilities under adversarial
and geometrically asymmetric attack paradigms. Our extended analysis demonstrates that
gradient-based adversarial perturbations reduce ZoDiac’s WDR, a threat model absent in
prior evaluations. We also investigate rotationally asymmetric attacks achieving WDR be-
low 65%. Additionally, we explore a new loss function to mitigate these limitations. Despite
these enhancements, composite attacks combining adversarial noise with other methods re-
duce WDR to near-zero, exposing vulnerabilities through multi-stage offensive pipelines.
Our implementation can be found on Anonymous Github.
URL: https://openreview.net/forum?id=l6QJfoIl1c
---
Title: VirDA: Reusing Backbone for Unsupervised Domain Adaptation with Visual Reprogramming
Abstract: Image classification is the foundation of nearly all computer-vision pipelines. While state-of-the-art models excel within their training domains, their performance often deteriorates when transferred to a new, unlabeled setting. Unsupervised domain adaptation (UDA) addresses this challenge by repurposing a well-trained source classifier for the target domain, enabling strong downstream results without the need for additional labeled data. Existing UDA pipelines fine-tune already well-trained backbone parameters for every new source-and-target pair, resulting in the number of training parameters and storage memory growing linearly with each new pair, and also preventing the reuse of these well-trained backbone parameters.
Inspired by recent implications that existing backbones have textural biases, we propose making use of domain-specific textural bias for domain adaptation via visual reprogramming, namely \method{}.
Instead of fine-tuning the full backbone, \method{} prepends a domain-specific visual reprogramming layer to the backbone. This layer produces visual prompts that act as an added textural bias to the input image, adapting its ``style'' to a target domain. To optimize these visual reprogramming layers, we use multiple objective functions that optimize the intra- and inter-domain distribution differences when domain-adapting visual prompts are applied. This process does not require modifying the backbone parameters, allowing the same backbone to be reused across different domains.
We evaluate \method{} on Office-31 and obtain 92.8\% mean accuracy with only 1.5M trainable parameters. \method{} surpasses PDA, the state-of-the-art parameter-efficient UDA baseline, by +1.6\% accuracy while using just 46\% of its parameters. Compared with full-backbone fine-tuning, \method{} outperforms CDTrans and FixBi by +0.2\% and +1.4\%, respectively, while requiring only 1.7\% and 2.8\% of their trainable parameters. Relative to the strongest current methods (PMTrans and TVT), \method{} uses ~1.7\% of their parameters and trades off only 2.2\% and 1.1\% accuracy, respectively.
URL: https://openreview.net/forum?id=Qh7or7JRFI
---
Title: Are Data Embeddings effective in time series forecasting?
Abstract: Time series forecasting plays a crucial role in many real-world applications, and numerous complex forecasting models have been proposed in recent years. Despite their architectural innovations, most state-of-the-art models report only marginal improvements—typically just a few thousandths in standard error metrics. These models often incorporate complex data embedding layers, which typically transform raw inputs into higher-dimensional representations to enhance accuracy. But are data embedding techniques actually effective in time series forecasting? Through extensive ablation studies across fifteen state-of-the-art models and four benchmark datasets, we find that removing data embedding layers from many state-of-the-art models does not degrade forecasting performance—in many cases, it improves both accuracy and computational efficiency. The gains from removing embedding layers often exceed the performance differences typically reported between competing state-of-the-art models.
URL: https://openreview.net/forum?id=yeu44ZRvZZ
---
Title: Augmenting Molecular Graphs with Geometries via Machine Learning Interatomic Potentials
Abstract: Accurate molecular property predictions require 3D geometries, which are typically obtained using expensive methods such as density functional theory (DFT). Here, we attempt to obtain molecular geometries by relying solely on machine learning interatomic potential (MLIP) models. To this end, we first curate a large-scale molecular relaxation dataset comprising 3.5 million molecules and 300 million snapshots. Then MLIP foundation models are trained with supervised learning to predict energy and forces given 3D molecular structures. Once trained, we show that the foundation models can be used in different ways to obtain geometries either explicitly or implicitly. First, it can be used to obtain low-energy 3D geometries via geometry optimization, providing relaxed 3D geometries for downstream molecular property predictions. To mitigate potential biases and enhance downstream predictions, we introduce geometry fine-tuning based on the relaxed 3D geometries. Second, the foundation models can be directly fine-tuned for property prediction when ground truth 3D geometries are available. Our results demonstrate that MLIP foundation models trained on relaxation data can provide valuable molecular geometries that benefit property predictions.
URL: https://openreview.net/forum?id=JwxhHTISJL
---
Title: Exploring Training Data Attribution under Limited Access Constraints
Abstract: Training data attribution (TDA) plays a critical role in understanding the influence of individual training data points on model predictions. Gradient-based TDA methods, popularized by \textit{influence function} for their superior performance, have been widely applied in data selection, data cleaning, data economics, and fact tracing. However, in real-world scenarios where commercial models are not publicly accessible and computational resources are limited, existing TDA methods are often constrained by their reliance on full model access and high computational costs. This poses significant challenges to the broader adoption of TDA in practical applications.
In this work, we present a systematic study of TDA methods under various access and resource constraints. We investigate the feasibility of performing TDA under varying levels of access constraints by leveraging appropriately designed solutions such as proxy models. Besides, we demonstrate that attribution scores obtained from models without prior training on the target dataset remain informative across a range of tasks, which is useful for scenarios where computational resources are limited. Our findings provide practical guidance for deploying TDA in real-world environments, aiming to improve feasibility and efficiency under limited access.
URL: https://openreview.net/forum?id=4O0bwYy4Yu
---
Title: Parameter Efficient Continual Learning with Dynamic Low- Rank Adaptation
Abstract: Catastrophic forgetting has remained a critical challenge for deep neural networks in Continual Learning (CL) as it undermines consolidated knowledge when learning new tasks. Parameter efficient fine-tuning CL techniques are gaining traction for their effectiveness in addressing catastrophic forgetting with lightweight training schedule while avoiding degradation of consolidated knowledge in pre-trained models. However, low-rank adapters (LoRA) in these approaches are highly sensitive to rank selection as it can lead to sub-optimal resource allocation and performance. To this end, we introduce PEARL, a rehearsal-free CL framework that entails dynamic rank allocation for LoRA components during CL training. Specifically, PEARL leverages reference task weights and adaptively determines the rank of task-specific LoRA components based on the current task’s proximity to reference task weights in parameter space. To demonstrate the versatility of PEARL, we evaluate PEARL across three vision architectures (ResNet, Separable Convolutional Network, and Vision Transformer) and a multitude of CL scenarios, and show that PEARL outperforms all considered baselines by a large margin.
URL: https://openreview.net/forum?id=ZqQATq0Geg
---
Title: Steering Dialogue Dynamics for Robustness against Multi- turn Jailbreaking Attacks
Abstract: Large language models (LLMs) are shown to be vulnerable to jailbreaking attacks where adversarial prompts are designed to elicit harmful responses. While existing defenses effectively mitigate single-turn attacks by detecting and filtering unsafe inputs, they fail against multi-turn jailbreaks that exploit contextual drift over multiple interactions, gradually leading LLMs away from safe behavior. To address this challenge, we propose a safety steering framework grounded in safe control theory, ensuring invariant safety in multi-turn dialogues. Our approach models the dialogue with LLMs using state-space representations and introduces a novel neural barrier function (NBF) to detect and filter harmful queries emerging from evolving contexts proactively. Our method achieves invariant safety at each turn of dialogue by learning a safety predictor that accounts for adversarial queries, preventing potential context drift toward jailbreaks. Extensive experiments under multiple LLMs show that our NBF-based safety steering outperforms safety alignment, prompt-based steering, and lightweight LLM guardrails baselines, offering stronger defenses against multi-turn jailbreaks while maintaining a better trade-off among safety, helpfulness, and over-refusal. Check out the website at https://sites.google.com/view/llm-nbf/home.
URL: https://openreview.net/forum?id=dcyLr9xYoI
---
Title: Proxy-Anchor and EVT-Driven Continual Learning Method for Generalized Category Discovery
Abstract: Continual generalized category discovery has been introduced and studied in the literature as a method that aims to continuously discover and learn novel categories in incoming data batches while avoiding catastrophic forgetting of previously learned categories. A key component in addressing this challenge is the model’s ability to separate novel samples, where Extreme Value Theory (EVT) has been effectively employed. In this work, we propose a novel method that integrates EVT with proxy anchors to define boundaries around proxies using a probability of inclusion function, enabling the rejection of unknown samples. Additionally, we introduce a novel EVT-based loss function to enhance the learned representation, achieving superior performance compared to other deep-metric learning methods in similar settings. Using the derived probability functions, novel samples are effectively separated from previously known categories. However, category discovery within these novel samples can sometimes overestimate the number of new categories. To mitigate this issue, we propose a novel EVT-based approach to reduce the model size and discard redundant proxies. We also incorporate experience replay and knowledge distillation mechanisms during the continual learning stage to prevent catastrophic forgetting. Experimental results demonstrate that our proposed approach outperforms state-of-the-art methods in continual generalized category discovery scenarios.
URL: https://openreview.net/forum?id=P3Qe9yJRvf
---
Title: Constant Rate Scheduling: A General Framework for Optimizing Diffusion Noise Schedule via Distributional Change
Abstract: We propose a general framework for optimizing noise schedules in diffusion models, applicable to both training and sampling.
Our method enforces a constant rate of change in the probability distribution of diffused data throughout the diffusion process,
where the rate of change is quantified using a user-defined discrepancy measure.
We introduce three such measures, which can be flexibly selected or combined depending on the domain and model architecture.
While our framework is inspired by theoretical insights, we do not aim to provide a complete theoretical justification of how distributional change affects sample quality.
Instead, we focus on establishing a general-purpose scheduling framework and validating its empirical effectiveness.
Through extensive experiments, we demonstrate that our approach consistently improves the performance of both pixel-space and latent-space diffusion models,
across various datasets, samplers, and a wide range of number of function evaluations from 5 to 250.
In particular, when applied to both training and sampling schedules, our method achieves a state-of-the-art FID score of 2.03 on LSUN Horse 256$\times$256, without compromising mode coverage.
URL: https://openreview.net/forum?id=Pjq6kdvMBj
---
Title: Lorenza: Enhancing Generalization in Low-Rank Gradient LLM Training via Efficient Zeroth-Order Adaptive SAM
Abstract: Modern applications often require fine-tuning large language models (LLMs) within strict memory and computational limits, but existing memory-efficient optimizers tend to compromise robustness and generalization. To tackle this, we introduce Lorenza, a low-memory optimizer based on Sharpness-Aware Minimization (SAM). Lorenza employs a stochastic zeroth-order estimator to approximate ascent directions, reducing the computational complexity of SAM while, as we prove, maintaining its convergence guarantees. Additionally, by applying randomized singular value decomposition, Lorenza performs efficient low-rank gradient updates, achieving memory efficiency similar to traditional methods. Our theoretical analysis and experiments demonstrate that Lorenza improves robustness and generalization, particularly in challenging language tasks. Furthermore, we present Lorenza+, which enhances Lorenza by incorporating the discarded orthogonal gradient component, resulting in additional performance gains without requiring extra memory or computational overhead.
URL: https://openreview.net/forum?id=YyA51ekcQo
---
Title: Learning object representations through amortized inference over probabilistic programs
Abstract: The recent developments of modern probabilistic programming languages have enabled the combination of pattern recognition engines implemented by neural networks to guide inference over explanatory factors written as symbols in probabilistic programs. We argue that learning to invert fixed generative programs, instead of learned ones, places stronger restrictions on the representations learned by feature extraction networks, which reduces the space of latent hypotheses and enhances training efficiency. To empirically demonstrate this, we investigate a neurosymbolic object-centric representation learning approach that combines a slot-based neural module optimized via inference compilation to invert a prior generative program of scene generation. By amortizing the search over posterior hypotheses, we demonstrate that approximate inference using data-driven sequential Monte Carlo methods achieves competitive results when compared to state-of-the-art fully neural baselines while requiring several times fewer training steps.
URL: https://openreview.net/forum?id=nUFSrlJaUr
---