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cs.CVcs.AIcs.LG Tianjiao Yu, Xinzhuo Li, Yifan Shen et al. · Oct 1, 2026

SILSA tackles the cost and topological fragility of high-resolution 3D generation by replacing dense or sparse voxel tokens with compact sliding-window slice latents along the three canonical axes. Each of the 384 fixed tokens summarizes a local depth window, preserving cross-sectional continuity while enabling a single-stage rectified-flow generator. Topology-aware slice supervision and a Volumetric Anchor Lattice then maintain geometric and structural coherence. The paper reports large efficiency gains—over 98% fewer tokens than sparse voxelizers—and solid improvements in PSNR, coverage, and Betti error.

High-resolution 3D generation increasingly relies on voxel latents and multi-stage pipelines that first predict active structure and then synthesize local geometry. While effective, this design fragments continuous surfaces into many local tokens, inflates generation cost, and often weakens topological consistency for thin or highly connected shapes. We introduce SILSA, a topology-aware 3D generation framework that represents shapes with compact sliding-window slice latents. Instead of generating expensive voxel tokens, SILSA uses a fixed set of overlapping slices along the three canonical axes, where each token summarizes a local depth window to preserve cross-sectional continuity and support single-stage rectified-flow generation. A Slice VAE encodes oriented surface samples into multi-axis slice latents and reconstructs them with a sparse volumetric decoder, while a Volumetric Anchor Lattice coordinates directional slice streams through a shared 3D workspace. To preserve structural correctness, we introduce slice-level topology supervision that matches persistence diagrams and aligns Betti transitions across neighboring slices. Experiments show that SILSA improves structural fidelity while substantially reducing generation cost. SILSA improves PSNR by $8.7\%$, coverage by $5.96$ absolute points, and Betti error by $9.2\%$ over the strongest baseline, while using $70.0\%$ fewer tokens than the next-most compact baseline and over $98\%$ fewer tokens than sparse or hierarchical tokenizers, effectively reducing training memory by $40.4\%$ and inference time by $58.5\%$. Qualitative results further show improved preservation of thin structures, repeated components, and long-range connectivity.
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cs.LG Tristan Shah, Wooyoung Chung, Volodomyr Makarenko et al. · Oct 1, 2026

Unsupervised reinforcement learning aims to eliminate hand-crafted rewards, yet existing intrinsic motivation objectives either require selecting information variables or serve only as exploration bonuses. This paper introduces Forward CIP (F-CIP), an exact forward-in-time decomposition of the Controllable Information Production (CIP) objective—defined by the sum of positive open-loop Lyapunov exponents—into a per-step Markovian reward and a propagated information matrix memory. By doing so, it enables standard RL algorithms to unsupervisedly discover upright balancing and to simplify reward engineering for dynamic locomotion tasks.

Reinforcement learning (RL) is a powerful paradigm for training agents, yet its success rests on domain expertise of human engineers who design informative reward signals for every new task. Unsupervised RL aims to reduce this engineering with intrinsic motivation (IM): reward signals that emerge from the agent environment interaction itself. Existing IM objectives, however, involve the selection of information variables, which re-introduces domain expertise the field has sought to eliminate. We introduce Forward CIP (F-CIP), an RL-native formulation of the Controllable Information Production (CIP) objective, which is defined by the system's dynamics alone and requires no such selection. We prove that F-CIP is compatible with RL and demonstrate its effectiveness with existing algorithms. Training agents with F-CIP results in unsupervised discovery of primitive behaviors such as balancing and maintaining controllability, which are essential for more complex robot behaviors. Paired with a simple forward-velocity reward, our method produces coordinated gaits such as hopping and running which otherwise require reward engineering to learn.
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cs.SDcs.LGeess.AS Haider Al-Tahan, Sean O'Brien, Anastasia Razdaibiedina et al. · Oct 1, 2026

Sound classification with transformers usually demands stacking many layers, which inflates parameters and compute. LAST asks whether the same blocks can be reused to refine only a single class token while keeping audio features fixed, trading depth for recurrence. Their looped Audio Spectrogram Transformer matches or exceeds deeper sequential baselines on AudioSet at roughly half the parameter count, suggesting that how tokens are updated matters as much as how many layers exist.

Increasing depth of transformer models improves recognition, but it comes at a substantial cost. Each additional layer requires more parameters, which makes the process computationally inefficient. We ask whether additional processing can focus on integrating features already computed. Looped Audio Spectrogram Transformer (LAST) first processes all tokens, then reuses the same blocks to refine only the class token over fixed audio features, thereby making later passes inexpensive. On AudioSet, ten-pass LAST achieves 0.345 mean average precision, exceeding a twelve-layer sequential transformer by 2.1% relative with 49.4% fewer parameters, 42% fewer multiply-accumulate operations, and 9.8% higher measured throughput. Across separately trained models, increasing the pass count from two to ten improves accuracy while adding only 1.2% computation. Further evaluations show improved robustness to temporal masking and various other auditory augmentations, with better generalization on classification tasks with music, environmental, and event sounds.
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cs.CVcs.LG Hossein Maghsoumi, George Atia, Yaser P. Fallah · Oct 1, 2026

This work tackles street-view weather recognition under severe domain shift, where labeled training images come from generic outdoor datasets and real driving scenes are unlabeled at training time. The proposed Weather-Aware ADDA conditions the adversarial domain discriminator on predicted weather probabilities, encouraging alignment that remains sensitive to weather semantics. The idea is to enable reliable onboard camera-based perception for autonomous vehicles without requiring expensive labeled street-view data for every adverse condition.

Adverse conditions such as rain, snow, fog, and dust remain challenging for camera-based perception in autonomous driving. We study multi-class weather recognition from street-view images under domain shift, where most available training data come from non-street-view sources that differ markedly from real driving scenes. We propose Weather-Aware Adversarial Discriminative Domain Adaptation (WA-ADDA), which conditions the domain discriminator on predicted weather to promote features that are both domain-invariant and weather-sensitive. We also assemble a multi-dataset benchmark by unifying diverse non-street-view weather collections as sources and real street-view images as targets, and define a standardized evaluation protocol with macro accuracy as the primary metric. Across backbones (ResNet-50, EfficientNet, VGG, DenseNet), WA-ADDA consistently improves street-view performance and yields strong per-class recalls in challenging conditions while preserving clear-weather accuracy. These findings highlight the feasibility of domain-adapted weather recognition and the value of our benchmark for advancing robust, on-board perception.
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cs.LGcs.AI Yiming Huang, Yujie Zeng, Vijay Prakash Dwivedi et al. · Oct 1, 2026

This paper introduces Higher-order Grammar Representation (HGR), a method that lifts molecular graphs into combinatorial complexes and parses them into compact sequences of context-free production rules, making higher-order topology such as ring systems tractable for standard sequence models. To reduce benchmark bias toward simple rings, the authors also construct RingDiv, a ring-enriched benchmark of 1.18 million molecules. HGR is instantiated in generative models (HGR-VAE and HGR-LDF) and a foundation model (HGR-FM), with claims of 100% validity by construction and state-of-the-art distributional alignment and transfer performance.

Molecular learning models are strongly shaped by their underlying representations. Yet standard sequential and graph formalisms struggle to explicitly encode higher-order topology, such as ring systems and recurring motifs. Existing higher-order representations can capture these structures directly, but they are often computationally demanding and difficult to decode into valid molecules. Here, we introduce Higher-order Grammar Representation (HGR), a principled, topology-aware framework that lifts molecules to combinatorial complexes and parses each complex into a compact sequence of production rules under a context-free higher-order grammar. By serialising higher-order topology into rule sequences, HGR makes these structures directly compatible with standard sequence models, avoiding the computational overhead of explicit higher-order encodings while preserving topological expressiveness. To reduce benchmark bias towards simple ring systems, we construct RingDiv, a ring-enriched benchmark containing 1.18 million molecules, including the curated RingDiv300k subset, and introduce the ring diversity index (RDI) to quantify ring-system coverage. In molecular generation, HGR-based models uniquely combine 100% validity by construction with leading distributional alignment, ranking first in FCD on all five generation benchmarks. In representation learning, HGR-FM achieves the highest mean AUC across seven MoleculeNet benchmarks under both transfer protocols, improving on the strongest baseline by 8.3 and 3.3 AUC points under probing and full fine-tuning, respectively. Collectively, these results establish HGR as an efficient higher-order representation for molecular generation and transferable representation learning.
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cs.SDcs.CLcs.LG Serli Kopar, Alkis Koudounas, Roshan P. Rane et al. · Oct 1, 2026

Speech-based Alzheimer's assessment increasingly relies on self-supervised learning models, but their vulnerability to nuisance acoustic factors remains unclear. This paper asks whether noise and reverberation are merely encoded in SSL representations or actively drive diagnostic predictions. Using controlled input- and representation-space interventions on the ADReSSo dataset, the authors show that acoustic manipulations systematically shift classifier outputs even when no baseline group difference exists, challenging the assumption that predictive accuracy implies robustness.

Speech-based Alzheimer's disease (AD) assessments increasingly rely on pretrained self-supervised learning (SSL) models that learn acoustic representations directly from raw audio, exposing the model to recording factors. We ask whether such factors are merely encoded in SSL representations or can systematically alter predictions. Using ADReSSo and three large SSL backbones, we apply controlled noise and reverberation interventions to participant-speech-only, non-speech, and full-recording audio. We combine layer-wise linear decoding, input- and representation-space interventions, and geometric alignment analysis to distinguish acoustic decodability from influence on AD prediction. Our results show that controlled acoustic interventions alter AD predictions across all three SSL backbones. Noise, despite showing no significant diagnostic-group difference in the original data, produces the strongest intervention effects. Importantly, these effects are systematically structured relative to the classifier's decision direction, replicate on the held-out test set and reverse when the representation-space intervention direction is reversed. Together, these findings show that high predictive performance and the absence of a significant diagnostic-group difference in a measured acoustic factor are not sufficient for robustness. We argue that intervention-based robustness tests should become standard for trustworthy clinical speech models.
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cs.LG Daniel Bethell, Charmaine Barker, Simos Gerasimou · Oct 1, 2026

Deep neural networks in long-lived systems often face task obsolescence, where previously valid outputs become invalid after deployment. Deep Repurposing (DR) addresses this by analytically redirecting obsolete latent structure toward retained regions instead of simply erasing it. This enables lightweight post-hoc adaptation without gradient updates, achieving retained performance comparable to or better than unlearning and editing baselines while operating up to 60× faster than retraining.

Deep neural networks are increasingly deployed in long-lived systems, where task requirements may change after training. In such settings, part of the original output space may become obsolete: a class, prediction region, or learned behaviour may no longer be valid. Existing approaches either leave the obsolete behaviour intact or require fine-tuning, which can be expensive. We propose Deep Repurposing (DR), a post-hoc framework for adapting models under task obsolescence. DR estimates the latent geometry of obsolete and retained regions, removes obsolete-supporting components, and reallocates retained-compatible evidence through an analytic repair map without gradient updates. This yields repaired predictions and representations in which obsolete regions no longer act as valid outputs, while useful obsolete structure can support the retained task. Across multiple task settings, DR removes obsolete behaviour while preserving retained utility. More importantly, across classification benchmarks, DR matches or exceeds competing unlearning and editing baselines in retained accuracy, eliminates obsolete predictions, and adapts up to $60\times$ faster than competing unlearning methods.
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cs.CVcs.LG Asaf Vanunu, Boaz Nadler, Arnon Karnieli · Oct 1, 2026

Operational geostationary fire products like the GOES Fire Detection and Characterization (FDC) suffer from high false-alarm rates and poor nighttime recall. This study replaces the FDC's rule-based algorithm with a CatBoost gradient-boosting model trained on over 60,000 GOES ABI fire pixels labeled by VIIRS active-fire detections. By evaluating on large 2024 regions outside the training domain, the authors show that a comparatively simple ML model can substantially outperform the operational product in precision, recall, and early detection latency, especially after dark.

Wildfires pose severe risks to human life, ecosystems, and property. This study presents a machine learning approach for wildfire detection from GOES ABI imagery. A CatBoost model was trained on a large dataset with thousands of ABI images and over 300,000 matching VIIRS fire detections. An evaluation on a separate dataset across five regions showed that the learned CatBoost model outperformed the operational GOES Fire Detection and Characterization (FDC) product. It achieved higher precision, recall, and F1 scores both within and outside the training area. The CatBoost model achieved F1 scores that were 0.16 to 0.38 higher than the GOES FDC in all regions. In addition, out of 51 historical fire events, the CatBoost detected 26 fires before both VIIRS and GOES FDC, compared to only six earlier detections by the GOES FDC. Importantly, the CatBoost model achieved accurate wildfire detection also during nighttime, whereas the GOES FDC obtained very low recall values, around 0.03. This study demonstrates that machine learning models may offer significant improvements over existing geostationary fire products, including higher accuracy, fewer false alarms, and earlier detection.
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quant-phcs.LG Yibin Wang · Oct 1, 2026

How complex can a quantum device's responses become when it runs longer with a fixed internal memory? This paper quantifies this through sequential response capacity—the depth of an adaptively shattered binary tree of experiments—and proves a tight law: for fixed visible and memory dimensions, capacity grows as $\Theta(K\log((K+1)/\gamma))$ in run length $K$ and probability gap $\gamma$. The core construction shows that memory-one qubit phase channels already attain this scaling with exact zero-or-one responses, while fully measured classical processes under the same tester permissions are limited to linear capacity. The result establishes a fundamental information-theoretic separation between coherent quantum control and classical stochastic transitions under a finite memory budget.

How complex can the responses of a quantum device become as it runs longer with a fixed internal memory? We quantify this complexity through sequential response capacity: how many adaptive testing stages, each using a fresh run, can continue to separate possible processes by a prescribed gap in response probabilities. For fixed system and memory sizes, we establish a tight law relating this capacity to run length and probability resolution. At fixed resolution, the capacity grows on the order of $K\log K$, where $K$ is the number of time steps in each run. Our construction attains this growth using time-dependent phase rotations on a single visible qubit with no additional internal memory; its tests give response probabilities exactly zero or one. Under the same tests, classical stochastic processes that measure in a fixed basis at every step have only linear capacity at fixed sizes and resolution. For phase sequences selected by a stored classical label, we then quantify how known independent Pauli noise changes this logarithmic enhancement. With ideal controls and weak residual phase noise after correction, we prove matching capacity bounds at a fixed small probability gap. These bounds identify the inverse residual phase-flip probability as the coherence timescale that limits the extra logarithmic growth.
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cs.LG Weihao Liu, Huangjie Zheng, Tianrong Chen et al. · Oct 1, 2026

Looped Transformers reuse the same parameter block across recurrent iterations, producing intermediate states that are usually discarded at decode time. This paper proposes LoopCD, a training-free contrastive decoding framework that treats an early recurrent state as a weak predictor to guide the final prediction, either in logit space (one extra output pass) or hidden-state space (zero extra overhead). The core insight is that recurrence naturally provides aligned weak-and-strong pairs without auxiliary models, and the authors show this can both boost accuracy at full depth and—more interestingly—allow halving the iterations while matching baseline performance, cutting forward FLOPs by roughly 23–48%.

Looped Transformers achieve parameter efficiency by repeatedly executing a shared block across recurrent loops. Each loop yields an intermediate representation decodable for the same next token, yet standard decoding discards earlier states. Because earlier loops embody less computation, recurrence inherently supplies aligned weak-and-strong prediction pairs without auxiliary models or external training. We introduce LoopCD, a training-free contrastive decoding framework that guides token selection by contrasting the final prediction with an earlier recurrent pass, operating either in logit space with one extra output pass (LoopCD-Logits) or in hidden-state space with zero output overhead (LoopCD-Hidden). Across four looped Transformer families, LoopCD delivers substantial, consistent gains at full recurrent depth: LoopCD-Logits raises Ouro-2.6B-Thinking's AIME 2024 pass@1 from 61.88% to 73.33%, while LoopCD-Hidden lifts Huginn's HumanEval pass@1 from 22.56% to 31.71%. Crucially, these performance gains enable halving the number of recurrent loops while still matching or exceeding full-depth unguided baselines, reducing forward FLOPs by 22.5% to 48.2%. By transforming intermediate recurrent states into effective guidance signals, LoopCD achieves superior decoding quality while substantially reducing inference compute.
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cs.LG Yusuf Afifi, Artur Kiulian, Anton Polishko et al. · Oct 1, 2026

The paper tackles the frozen-context bottleneck in outcome-based reinforcement learning for forecasting: prior work either pastes fixed research snippets into the prompt before training or lets a frozen model search only at test time, so the policy is never rewarded for gathering better evidence. The authors close this gap by building a multi-turn agentic harness from 2,100+ resolved Polymarket questions, filtering every search and page-read to pre-cutoff information, and training Qwen3.5-35B-A3B with single-epoch GRPO under the Brier-score reward $r=1-(p-y)^2$. The core advance is that the model learns when and what to search for as a temporally grounded skill, rather than optimizing a frozen context window. This matters because it moves forecasting from prompt engineering to genuinely learned research discipline, and the trained open model reportedly beats several frontier systems at roughly 5% of the inference cost.

Outcome-based reinforcement learning can train language models to forecast real-world events, but prior forecasting work either freezes research context before training or deploys agentic research only at test time, so the skill of gathering evidence is never shaped by the reward. We introduce an agentic forecasting environment, dataset, and harness built from 2,100+ resolved Polymarket questions; the agent acquires its own context at rollout time (web search, page reading, and financial time series, all restricted by layered leak filtering to information published before each question's cutoff), and we train Qwen3.5-35B-A3B (3B active parameters) on it with single-epoch GRPO under a Brier-score reward. Training changes how the agent interacts with information: calibration improves 30-40%, and search attempts fall from 3.8 to 2.25 per rollout as evidence discipline is learned. Evaluated in an identical harness against four frontier models, the trained policy also finishes ahead of every frontier model tested at evidence-based forecasting, including Claude Opus 4.5 (soft-Brier 0.254 vs. 0.256, n=265), at about 5% of the inference cost, and its margin is widest on the hardest questions, the ones the crowd itself had not decided. We release the environment, dataset, and per-rollout records as a reusable harness for temporal forecasting agents.
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cs.LG Haocun Ye, Xinlong Jiang, Qile Chen et al. · Oct 1, 2026

Multimodal reinforcement learning with verifiable rewards (RLVR) is widely assumed to improve visual reasoning when models are rewarded for correct answers. This paper exposes a critical gap: benchmark gains can be achieved without learning from images at all, and prolonged training can even erode visual grounding. The authors propose "visual resolvability"—designing tasks where visual evidence is strictly necessary for reward—and show that standard GRPO on carefully constructed counterfactual coordinate scenes drives genuine visual discovery, unlike conventional benchmark training.

Reinforcement learning with verifiable rewards (RLVR) improves vision-language benchmark scores even without visual information during training. With images at test, blind-trained models recover roughly half of the real-image gain at 3B and nearly four fifths at 7B. Prolonged real-image training can erode grounding while benchmark gains persist. Both findings expose the same gap: an image in the prompt is not an image in the learning signal. Our design rule, visual resolvability, asks that visual evidence be necessary for a correct answer and that the task remain learnable. We test it on counterfactual coordinate scenes in which the question stays fixed and the target is never named, so a correct answer requires finding the target in the image. With standard GRPO and correctness-and-format rewards, a 7B model raises its accuracy at finding the target (discovery) from 0.425 to 0.875 on held-out scenes denser than any it trained on, and it improves on question types it never trained on. Two controls locate the source of the gain. Replacing test images with gray canvases drops discovery to zero; training on gray canvases instead, at matched step 30 and in each of four seeds, yields essentially none of the gain even when the model is then tested with real images. The learned skill carries over to grounding tasks built independently of the training corpus. A caption that answers the training question, added to the same images, reward and budget, cuts the gain by nearly two thirds. Changing what reward requires changes what RL learns.
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cs.LG Simon Forbat, Rainer Gemulla · Oct 1, 2026

Relational learning with tabular foundation models currently relies on Deep Feature Synthesis (DFS), which flattens multi-table schemas into single tables via column-wise aggregations along meta-paths. This paper identifies two critical limitations of DFS—feature explosion and interaction blindness—and proposes RelICL, a training-free method that instead propagates row embeddings through the schema graph using the foundation model itself. By iteratively pooling and fusing embeddings, RelICL keeps the TFM-agnostic benefits of DFS while scaling to complex schemas and capturing cross-column interactions. The experimental study on 21 RelBench tasks shows RelICL matches state-of-the-art DFS approaches, though it does not dominate them outright.

Tabular foundation models achieve state-of-the-art performance on single-table tasks without any training. Recent work suggests that they are also well-suited for relational learning via deep feature synthesis (DFS), which flattens a relational schema into a single table by adding aggregates of the other tables' columns as features. This approach is appealing because it directly benefits from improvements to or customization of the underlying tabular foundation model. In this paper, we identify two key problems with DFS: feature explosion and interaction blindness. The first problem arises because the number of DFS features grows quickly as the schema becomes more complex, limiting scalability and performance. The second problem arises because column-wise aggregates do not account for feature interactions, limiting performance. We propose and explore an alternative method termed RelICL, which keeps the benefits of DFS but alleviates these two problems. At its heart, RelICL propagates and fuses information step by step through the schema graph, using the same tabular foundation model that is eventually used for prediction to do so. In our experimental study using RelBench tasks, RelICL was on par with the strongest approach based on deep feature synthesis.
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math.STcs.LGstat.ML Shivam Kumar, Nabarun Deb · Oct 1, 2026

Many applications require sampling from high-dimensional categorical distributions with local dependence, but discrete diffusion models lack end-to-end statistical guarantees. This paper introduces a pinning decomposition of the discrete score under uniform noising, showing that time dependence separates multiplicatively from target dependence for Markov random fields of order $d$. Building on this, the authors design a weight-sharing neural score learner and prove a sample-complexity rate of $\widetilde O_{\mathbb P}(S^d/n)$, replacing the ambient dimension $D$ with the interaction order $d$.

Many applications in statistics, economics, and physics require sampling from high-dimensional categorical distributions with local dependence structures. Examples include finite memory language models, Ising and Potts systems in statistical physics and protein folding, etc. In modern machine learning, discrete diffusions have emerged as a flexible approach for sampling such data, with strong empirical performance. Motivated by this, we develop learning methods with end-to-end sample complexity bounds for discrete diffusion with uniform noising under local dependence, which we model through low order Markov random fields (MRFs). Our main technical insight is a new \emph{pinning decomposition} of the discrete score. It shows that unlike in continuous diffusions, the score decomposes into components where the dependence on time separates multiplicatively from the dependence on the target. Building on this decomposition, we propose a \emph{weight-sharing neural score learner} and combine it with $\tau$-leaping to obtain an end-to-end sampling procedure. Rather than treating score-learning error as a black-box input, as is common in existing sampling analyses, we study the score learning error from finite data and derive optimal sampling guarantees with explicit dependence on the vocabulary size, the interaction order of the MRF, and the sample size. Moreover, our strategy trains a single score network across uniform noise levels while leaving the sampling discretization to be chosen at inference-time. This allows the same trained model to trade accuracy for computational cost as inference-time budgets vary. Numerical experiments on Potts, Ising, and tree-structured models show that weight-sharing score networks outperform fully connected ones for sampling long sequences.
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cs.LG Caleb Stam, Aagrim Hoysal, Sanjukta Krishnagopal · Oct 1, 2026

Graph positional encodings (PSEs) are computed from pairwise edges and inherently miss higher-order interactions such as triangles and cliques. The paper proposes to enrich standard graph models by computing positional encodings on lifted higher-order domains (e.g., clique complexes) and projecting them back to nodes, without altering the backbone. Its core theoretical insight is that lift-induced symmetric node operators can mix the eigenmodes of the original graph Laplacian $L$, placing them outside the class of scalar spectral filters $g(L)$. This yields a principled design rule---the commutator $[L,M] \neq 0$---and an experimental pipeline using Hodge-Laplacian encodings.

Many real-world systems exhibit higher-order interactions among groups of entities that cannot be captured by pairwise relationships alone. Graph Transformers and Graph Neural Networks increasingly rely on positional encodings to enrich graph representations, yet existing positional encodings are computed solely from the original graph and therefore cannot directly capture observed higher-order interactions. Topological Deep Learning addresses this limitation by lifting graphs to simplicial complexes, but typically requires performing message passing or attention on higher-order neural network representations. We introduce a representation learning paradigm that enriches graph representations with higher-order topology through positional encodings, enabling standard graph learning models to exploit lifted incidence structure without modifying the backbone. We derive a theoretical characterization of the expressivity of higher-order positional encodings, proving that node-level operators induced by higher-order lifts can mix graph Laplacian frequencies in ways that scalar graph spectral filters cannot. Guided by this theory, we instantiate higher-order positional encodings using Hodge Laplacians derived from clique complexes. Experiments with Graph Transformers on ZINC and controlled synthetic benchmarks demonstrate improvements in predictive performance, while a fixed-1-skeleton experiment shows that the pipeline can transmit higher-order information when cells are supplied independently of the graph. Together, our results establish higher-order positional encodings as a principled bridge between graph positional encodings and topological deep learning.
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cs.LG Francesco Vitale, Hangli Ge, Francesco Flammini · Oct 1, 2026

Monitoring contact wire geometry is essential to prevent catastrophic failures like pantograph destruction and contact wire breakage in railway systems. Existing vision-based methods track wire height and stagger, but they process these measurements without knowing where along the route they occur. This paper proposes spatially aligning pantograph-catenary telemetry to a GPS master grid, partitioning the route into geographic segments, and training a localized bidirectional LSTM-autoencoder per segment to detect collective anomalies. It targets the blind spot of geographic agnosticism in current industrial monitoring, arguing that location-aware models reduce false positives caused by natural topological variation.

Monitoring the Pantograph-Catenary System (PCS) provides insight into the health conditions of the pantograph and the railway infrastructure. Recent industrial solutions trace the pantograph's contact wire height and stagger (PCS height/stagger) using video monitoring through convolutional neural networks. However, these solutions do not account for the train route's geographic location. Therefore, in this paper we propose a novel framework for 1) localization of the PCS height/stagger by alignment with the nominal GPS coordinates of the reference route, and 2) collective anomaly detection to evaluate the health conditions of the PCS. We apply and assess the localization and detection performance of the methodology to a case-study based on a real-world industrial dataset provided by a railway transportation company, which includes the PCS height/stagger of several train journeys across Italian railway routes.
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cs.LG Zailong Tian, Yanzhe Chen, Zhuoheng Han et al. · Oct 1, 2026

LoRA adapters often suffer from adaptation imbalance, where a handful of singular directions hoard the update energy and hurt both target-task specialization and off-task capability retention. This paper proposes LoRA-Norm, a data-free post-training edit that preserves the learned singular directions but rebalances their gains with a fixed hybrid Newton-Schulz transform and per-module nuclear-norm restoration. The authors argue that learning where to adapt does not ensure that adaptation gains are well balanced, and they evaluate the method on 18 adapters spanning two 8B backbones and three tasks.

While Low-Rank Adaptation (LoRA) enables efficient task specialization, its learned updates can compromise capabilities beyond the target task. We identify \textbf{adaptation imbalance}: a few singular directions dominate the trained update, leaving its performance sensitive to how gains are allocated. We argue that \textbf{learning where to adapt does not ensure that adaptation gains are well balanced}. This motivates \textbf{LoRA-Norm}, a post-training normalization method that retains learned directions while rebalancing their gains. LoRA-Norm combines spectral rebalancing, a fixed nonlinear transformation of singular values, with nuclear-norm restoration, which preserves the original total spectral mass. It requires no calibration data or additional training and introduces no inference overhead. Across two backbones and three adaptation tasks, LoRA-Norm improves average specialization and capability retention, outperforming the evaluated post-hoc spectral pruning and gradient-guided editing configurations on both measures. Stronger functional equalization brings no consistent additional gains, revealing that balancing adapter gains and equalizing their responses are distinct objectives.
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cs.LG Nafiseh Ghoroghchian, Haipeng Zhang, Shuyi Han et al. · Oct 1, 2026

Time series foundation models post strong scores on large benchmarks, yet their grasp of basic temporal logic remains unclear. This paper introduces SimpleTimeBench, a diagnostic suite of univariate and multivariate unit tests for primitives such as linear trends, periodic signals, and deterministic leading-indicator covariates. The authors show that prominent zero-shot TSFMs—including Chronos-2, Moirai, and Toto—fail on several trivial tasks, and that targeted fine-tuning on the full suite yields only marginal gains, suggesting that pre-training scale alone has not bought robust fundamental reasoning.

Despite the success of Time Series Foundation Models (TSFMs) on broad benchmarks, their ability to internalize basic temporal logic, especially in settings supported by exogenous covariates, remains under-examined. We introduce SimpleTimeBench, a diagnostic univariate and multivariate "unit test" suite for primitives such as monotonic trends, periodic signals and leading indicator covariates, scenarios where near-perfect forecasts should be trivial. Surprisingly, prominent multivariate TSFMs (Chronos-2, Moirai and Toto) frequently produce suboptimal zero-shot forecasts for these inputs. While fine-tuning Chronos-2 improves its behaviour on specific tasks, we show that this adaptation degrades performance on other fundamental patterns rather than enhancing its generalizable foundational capabilities. This reveals a gap between pre-training scale and basic temporal reasoning, suggesting that current TSFMs could potentially lack the inductive biases needed to capture simple predictable functions. We further demonstrate that these failures are not merely synthetic curiosities: they persist in real-world sensor forecasting, where TSFMs consistently underutilize leading indicators available in observed covariates. This inability to capture simple relationships limits the practical utility and reliability of current multivariate models.
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cs.LGstat.ML Nam Nguyen, Tuan Quang Dam · Oct 1, 2026

This paper studies fixed-confidence best-arm identification for Bernoulli bandits using the top-two $\beta$-EB-TCI rule, where the challenger is selected by a penalized Bernoulli GLR index. Its core contribution is a sharp non-asymptotic analysis: once the true best arm becomes the permanent leader and its sampling fraction stays near $\beta$, the stopping time is $T_\beta^\star(\mu)\log(1/\delta)$ up to lower-order terms. The paper also identifies exactly where the analysis stalls for the unguarded rule when suboptimal means are tied, and closes the gap with a mild $O(\sqrt{Kt})$ exploration guard.

Top-two algorithms are simple and effective for fixed-confidence best-arm identification, but their sharp non-asymptotic behavior is still not well understood. We study this problem for Bernoulli bandits through $\beta$-EB-TCI, the empirical-best top-two rule of Jourdan et al., whose challenger is chosen using a Bernoulli transportation cost with a logarithmic count penalty. We prove that, after the empirical leader has become the true best arm and its sampling fraction stays close to $\beta$, the stopping time is $T_{\beta}^{\star}(\mu)\log(1/\delta)$ up to lower-order concentration terms. We also show that, in this regime, every challenger is sampled linearly often. Thus, for the original algorithm without forced exploration, the main remaining difficulty is to control when the empirical leader becomes permanently correct. These results imply a non-asymptotic high-probability bound for all Bernoulli instances with a unique best arm. If the algorithm satisfies a finite-mean sufficient-exploration condition, the bound further yields the sharp expected sample complexity. In particular, this gives the sharp expectation result for the unguarded Bernoulli rule when all arm means are pairwise distinct, using the sufficient-exploration result of Jourdan et al. Finally, if we add a mild forced-exploration rule that contributes only $O(\sqrt{Kt})$ pulls up to time $t$, we obtain a self-contained expected sample-complexity theorem for any number of arms under the unique-best-arm assumption. We also identify a limitation of proof strategies that try to handle equal suboptimal means through a single index-comparison argument.
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cs.CRcs.AIcs.LG Emmanuela Andam, Yasir Abbas Zaidi, Abdelali Hadir et al. · Oct 1, 2026

This paper targets few-shot ransomware detection by pairing an Autoencoder Feature Extractor (AFE) with a Model-Agnostic Meta-Learning (MAML) classifier. The idea is to compress 72 tabular behavioral features into a 64-dimensional latent space via the autoencoder, then let MAML adapt a binary classifier from just a handful of labeled malware-versus-benign samples. The authors pitch this as a rapid-deployment defense for healthcare and critical infrastructure settings where new ransomware variants appear with little warning.

Ransomware has emerged as a major cybersecurity threat, with incidents increasing in frequency and impact across critical sectors. These attacks are typically launched through phishing emails, malicious downloads, or exploitation of software vulnerabilities to gain system access. Once inside, the malware encrypts files and demands a ransom, often in cryptocurrency, for the decryption key. Conventional detection methods often struggle with novel or scarce samples, leaving systems vulnerable. To address these challenges, this paper proposes a hybrid deep learning framework that combines an Autoencoder Feature Extractor (AFE) with a Model Agnostic Meta Learning (MAML) classifier for few shot malware detection. The AFE generates compact latent features that reduce noise and dimensionality, while the MAML classifier rapidly adapts to new threats using limited labeled data. Experiments conducted on the Ransomware Dataset 2024 demonstrate the effectiveness of the framework in binary classification tasks. Across one to fifty shot settings, the proposed model consistently achieves high accuracy, F1 score, and Matthews Correlation Coefficient values, maintaining reliable classification even under extreme scarcity. These results highlight the model's robustness and effectiveness in adapting to limited data scenarios, demonstrating the potential of combining feature extraction with meta learning to enhance resilience against malware, particularly in sectors such as healthcare, manufacturing, and public infrastructure, where cyberattacks can cause significant operational and financial disruption.