Your paper timeline
Scroll AI takes the way you would scroll a great paper aggregator: quick signal first, deeper critique when something earns your attention, and challenges when a claim feels off.
797 papers in cs.LG
Trending mixes fresh papers with community signal.
0
quant-phcs.LG Sota Hashimoto, Akinori Kawachi · Oct 1, 2026

Hashimoto and Kawachi study Hamiltonian function learning: predicting $\operatorname{Tr}[f(H)\rho]$ from classical descriptions of a Hamiltonian $H$ and state $\rho$ when the function $f$ is fixed and known. Their core result is a rigorous average-case classical hardness proof for two explicit instances—$f_{\cos,\pi}(\lambda)=\cos(\pi\lambda)$ and $f_{\exp,\beta}(\lambda)=e^{-\beta\lambda}$—obtained by reducing from the hardness of factoring random RSA moduli via Shor's algorithm embedded in projector Hamiltonians. This settles an open problem left by Morohoshi et al. and gives a computational quantum advantage in a quantum machine learning task that has already been demonstrated experimentally on superconducting devices.

Morohoshi, Nakayama, Manabe, and Mitarai proposed a physically motivated quantum machine learning problem in which the goal is to predict quantities of the form $\operatorname{Tr}[f(H)\rho]$ from classical descriptions of a Hamiltonian $H$ and a quantum state $\rho$, where $f$ is an unknown function. We call this problem Hamiltonian function learning in this paper. They constructed an efficient quantum learning algorithm under suitable conditions, while leaving a rigorous proof of average-case classical hardness open. In this paper, we rigorously prove the average-case classical hardness for two distribution-specific Hamiltonian function learning problems for $f_{\cos,\pi}(\lambda)=\cos(\pi\lambda)$ and $f_{\exp,\beta}(\lambda)=e^{-\beta\lambda}$ discussed in the paper of Morohoshi et al. under the assumption of the average-case hardness of factoring random RSA moduli. More specifically, we show that an efficient classical randomized learner under squared loss whose output hypotheses are evaluable in classical polynomial time for either problem would yield a classical randomized polynomial-time algorithm for factoring random RSA moduli.
0
cs.LG Chaiho Shin, Kwangsoo Kim · Oct 1, 2026

GLoC-EHR addresses clinical outcome prediction and reasoning over structured EHRs by equipping a language model with two complementary memories: a compact global trajectory summary and a bounded local set of selected events. The architecture aligns both routes with clinical text through hospital-course generation and masked-concept description recovery, then learns record-grounded, evidence-cited reasoning via GRPO with rewards for answer correctness and lexical evidence matching. Its core contribution is showing that a small multimodal LLM can match strong direct-prediction AUROCs while producing interpretable rationales tied to the patient record.

Structured electronic health records (EHRs) contain a patient's clinical trajectory as a sequence of clinical codes. Answering clinical questions from such records requires both the context of the whole trajectory and the specific events that support the answer. We introduce GLoC-EHR, a multimodal language model that reads a contextual encoding of the record through a fixed-size global memory of the trajectory and a local memory of selected events. The model learns to generate hospital-course summaries from the global memory and descriptions of masked concepts from the local memory, aligning both with clinical text. It is then trained to cite evidence before answering, through rationale fine-tuning followed by group relative policy optimization (GRPO) with rewards for correct answers and record-supported evidence. On three MIMIC-IV outcome tasks, GLoC-EHR attains the highest macro AUROC among the compared models when it answers directly, whereas zero-shot LLMs reading the serialized record fall far behind. With evidence-cited reasoning, it stays close to its direct multi-task counterpart in macro AUROC, and the evidence terms of the objective reduce unsupported evidence at a similar macro AUROC. The local memory adds distinct supported findings, particularly under strict matching, without a detectable change in macro AUROC. Without retraining, GLoC-EHR transfers to EHRSHOT on par with EHR-BERT and answers two unseen laboratory questions better than zero-shot prompting of its own backbone.
0
cs.LG Laziz U. Abdullaev, Minh-Hieu Pham, Bach Do et al. · Oct 1, 2026

This paper tackles the rigidity of standard Difference-in-Means (DiM) activation steering, which applies a single global vector to all activations and ignores nonlinear manifold structure. The authors propose Kernelized Activation Steering (KAS), lifting steering into a reproducing kernel Hilbert space so that each activation receives a locally adaptive, implicit update based on kernel similarities to source and target reference sets. The framework strictly generalizes DiM—recovering it under a linear kernel—and connects activation steering to maximum mean discrepancy witness functions, with empirical evaluations on jailbreaking, behavioral control, and image style generation.

Activation steering provides a simple, training-free mechanism for controlling attributes of generative models such as sentiment, style, and helpfulness. However, standard approaches such as Difference-in-Means apply a single input-independent steering vector across all activations, limiting expressivity and ignoring the local geometry of the activation space. We propose Kernelized Activation Steering (KAS), a unifying framework that lifts activation steering into a reproducing kernel Hilbert space. KAS formulates steering as an optimization problem expressed purely via kernel evaluations, yielding an implicit, activation-dependent steering score without constructing explicit feature maps. Unlike DiM, KAS induces locally adaptive steering: each activation is modified according to its relative position with respect to source and target reference sets, producing a nonlinear steering field over the representation space. Importantly, DiM is recovered as a special case under a linear kernel, while richer kernels enable geometry-aware interventions. Across standard activation steering tasks, including jailbreaking LLMs and image style control, KAS outperforms or is on par with the existing methods.
0
stat.MLcs.LGstat.ME Jie Tang, Chuanlong Xie, Lixing Zhu · Oct 1, 2026

Most fairness tests ask whether a model treats groups exactly equally, but real audits often need to decide whether a disparity exceeds a legally or practically meaningful tolerance. This paper formalizes tolerance-based fairness auditing as two distinct statistical objectives—formal violation certification and early-warning sensitivity screening—and develops empirical-likelihood procedures calibrated to each. Constrained empirical likelihood (CEL) controls false violation declarations over a tolerance region, while split empirical likelihood (SEL) and an adjusted variant (ASEL) use an adaptive boundary-proxy principle to increase detection near the boundary. The work matters because it translates abstract fairness requirements into actionable, objective-dependent statistical guarantees.

As artificial intelligence is increasingly deployed, algorithmic unfairness has raised growing concerns and intensified demands for transparent fairness auditing. In practice, the tolerable degree of algorithmic unfairness depends on the specific legal, ethical, or application context. Given a prespecified tolerance threshold, an important statistical question is how to determine whether a group disparity exceeds the allowable tolerance across different auditing objectives. To address this problem, we develop a unified tolerance-based fairness auditing framework for two complementary auditing objectives: violation certification, which prioritizes control of false violation declarations, and sensitivity screening, which prioritizes reducing missed violations. For the first objective, we develop a constrained empirical likelihood test for formal settings that uses least-favorable-point calibration and can be combined with false flagging rate control for simultaneous subgroup auditing. For the second objective, we develop split empirical likelihood and adjusted split empirical likelihood tests using an adaptive boundary-proxy principle for early-warning settings. Numerical experiments show the distinct error-control--sensitivity trade-offs of these procedures. A COMPAS analysis illustrates the framework in predictive fairness auditing.
0
stat.MLcs.LGstat.ME Marco Pollanen · Oct 1, 2026

Treating model release as a design problem rather than a convention, this paper asks how many of $k$ automated tests a model should pass before deployment to guarantee a stated reliability target while retaining as many good models as possible. Using a two-class Gaussian latent-factor model with common within-class correlation $\rho$, the author proves that precision rises strictly with the required pass count $r$, so the optimal gate is the most lenient $r$-of-$k$ rule that meets the target. This matters because teams often default to pass-all gating, which can decimate the pool of acceptable models when tests are even modestly correlated; the paper shows that misjudging dependence by a factor of two can hurt more than shifting the gate by one test.

Before a machine learning model ships, it often has to pass a suite of automated tests. Requiring every test to pass looks safe, yet it can reject many models that would have served users well, and it does not say how trustworthy a passing model actually is. We treat the release gate as a design problem: choose how many tests a model must pass so that cleared models meet a stated reliability target, while keeping as many good models as possible. A two-class latent-factor model makes both costs explicit and reduces each calculation to a one-dimensional integral. We prove that when both classes share the same latent correlation, a stricter gate always raises reliability, so the gate that keeps the most good models is the most lenient one that still meets the target. Under pass-all gating, any reliability target short of perfection is attainable within the model, but the share of good models kept tends to zero as the suite grows. Correlation between tests sets the price. In one configuration, a 99 percent target needs 8 independent tests, but 74 tests at a latent correlation of 0.3 and 5,182 at 0.5, where the gate keeps fewer than one good model in ten. We also give a validation procedure, built on exact binomial bounds, that certifies a gate from labelled data even when the gate is chosen from a fixed shortlist.
0
cs.LG Jonathan Williams, Esin Tureci Karthik R. Narasimhan · Oct 1, 2026

The paper identifies a failure mode in the standard RLVR pipeline: training one policy with reinforcement learning from verifiable rewards (RLVR) improves single-sample accuracy but can hurt majority-vote performance because RLVR increases correlation among voter errors and collapses output diversity. The proposed fix is an "adapter thicket" — splitting the same training budget across $K$ independent LoRA adapters, each trained on a disjoint random data shard. Across 16 (model, $K$) settings and four models (1.5B–8B), thickets consistently out-vote the fully trained single adapter, and for $K \geq 4$ they protect the base model's vote while keeping most of the single-sample gain.

Majority voting over sampled completions is the workhorse of test-time scaling, and reinforcement learning with verifiable rewards (RLVR) is the workhorse for making each completion better. The standard pipeline composes the two: train one policy with RLVR, then sample it many times and vote. We show that this composition is lossy. A vote can only overturn mistakes that its voters do not share, and RLVR sharpens a policy so that its samples increasingly make the same mistakes. With every method drawing exactly $160$ completions per problem, training a single LoRA adapter on the full RLVR budget raises single-sample accuracy on every model we test ($1.5$B-$8$B). Yet on three of four models it leaves the majority vote below that of the untrained base model, by up to $4.8$ points. The damage builds during training: voter errors grow steadily more correlated, and the majority vote accuracy peaks early before falling by up to $7.0$ points. The cause is concentration, not RLVR itself. We split the same data and training budget across $K$ LoRA adapters, each trained on its own random disjoint shard, and call the result an adapter thicket. Thickets out-vote the fully trained adapter in all $16$ (model, $K$) settings, and for $K{\geq}4$ they stay within $0.8$ points of the base model or above it. A single adapter stopped early, at a thicket member's step count, is a strong control that matches thickets for small $K$. For $K{\geq}8$, thickets keep more of RLVR's single-sample gain and out-vote this control in six of eight settings. The cost of concentration also grows with the number of votes: from $16$ to $160$ votes, the thicket's lead over the fully trained adapter widens from $1.3$ to $3.3$ points. When the plan is to sample and vote, an RLVR budget is better spent broad than deep.
0
cs.LGq-bio.BM Shan Yu, Xuening Wu · Oct 1, 2026

Detecting cryptic ligand-binding pockets from unbound protein structures is difficult because the pockets are often absent or closed in apo conformations. The authors propose an algebraic counting field (ACF) that maps explicit local structural features into compact, integer-weighted lookup tables so that every residue score can be mechanically reconstructed from training counts and spatial aggregation. The goal is to achieve competitive cryptic-pocket prediction while keeping the inference fully auditable, without relying on sequence homology, structural templates, or deep learning at inference time.

Cryptic ligand-binding pockets are not apparent in experimentally determined apo structures, making them difficult to identify from unbound receptor geometry. A complementary challenge is to make the structural measurements and learned evidence behind each prediction directly inspectable. We introduce a supervised algebraic counting field (ACF) for predicting cryptic-pocket residues from apo structures. ACF compiles explicit geometric, physicochemical, and topological features into compact, integer-weighted lookup tables. Each prediction score can be reconstructed from feature values, training counts, table weights, and spatial aggregation, without sequence search, structural-template transfer, or a protein language model at inference. We evaluate ACF on CryptoBench and two locked external collections, separating ranking performance from the effects of residue-calling budgets. On an external set of 57 post-CryptoBench apo-holo units, ACF exceeded P2Rank by +0.044 in mean paired ROC-AUC (multiplicity-adjusted 95% CI [+0.010, +0.079]). The advantage was dataset-dependent: official-fold ROC-AUC and matched-budget F1 differences against P2Rank remained unresolved, and a second external evaluation did not confirm gains from added structural features. ACF thus provides a compact predictor with externally validated signal and an inspectable path from structural measurements and training counts to residue scores.
0
cs.LGcs.RO Oliver Obst, Frieder Stolzenburg · Oct 1, 2026

In model-predictive control with the cross-entropy method, a learned world model scores candidate action sequences and refits the Gaussian proposal for the next search iteration, creating planner-induced query shift. The authors disentangle these two roles by saving every CEM candidate pool from four surrogate models, executing all candidates in a resettable environment for a ground-truth ranking, and rescoring each pool with every model in a crossed design; they then splice the first elite set with environment-ranked elites to trace causal consequences through later iterations. Their results show that standard proposal distances contract even as ranking agreement stays near chance and mean disagreement grows, and that a single environment-guided elite update lowers final selected cost—demonstrating that world-model quality must be judged by its effect on the proposal, not just on candidate scoring.

The cross-entropy method (CEM) uses world-model scores to select action sequences and fit the distribution sampled in its next iteration. A scoring error can therefore change both the present decision and the candidates considered later. We evaluate these two roles separately. Four types of predictive model generate CEM traces, and every model rescores every saved candidate pool. Executing the same candidates in the environment provides a reference elite set and proposal update. Across twelve independently trained task-seed units on Walker and Cheetah, the pre-specified proposal distance falls from the first to the final CEM iteration in every unit. Proposal widths contract and fitted means separate relative to the remaining search width. Pairwise ranking agreement stays near chance on Walker and declines on Cheetah; elite-set agreement does not improve. This comparison shows greater variation between scorers than between pool sources on Cheetah; Walker has variation in both and in their pairings. We use the original six units to select Random nonlinear for a one-update intervention, without inspecting intervention outcomes. Replacing its first model-ranked update with an environment-ranked update lowers final realised selected-sequence cost in those six units and in six further units held out from the selection.
0
cs.LG Tilen Cadez, Sanghoon Lee, Kyoung-Min Kim · Oct 1, 2026

This work investigates how Kolmogorov-Arnold Networks (KANs) scale with training dataset size across three recent variants—BSRBF-KAN, Gottlieb-KAN, and Faster-KAN—on MNIST, Fashion-MNIST, and a magnetic-parameter regression task. The authors fit test loss versus dataset size with a smoothly broken power law, report regime crossings from random-guess to faster- and slower-scaling branches in classification, and analyze how the shapes of learnable edge functions evolve as data grows. The central takeaway is that KAN scaling is architecture-dependent and task-dependent, and that Gottlieb-KAN edge functions collapse into a single shape family rather than diversifying symbolically.

Kolmogorov-Arnold Networks (KANs) represent a compelling alternative to traditional Multi-Layer Perceptron (MLP)-based neural networks. By employing activation functions as learnable elements, KANs offer superior interpretability, making them suited for scientific domains. In this work, we investigate the neural scaling laws of KANs and the structural evolution of their learnable activation functions under dataset expansion. Specifically, we evaluate the scaling behavior of three KAN variants---BSRBF-KAN, Gottlieb-KAN, and Faster-KAN---across standard image classification benchmarks (MNIST and Fashion-MNIST) and a specialized scientific regression task (magnetic parameter estimation from domain images of moir\'e magnetic textures). Our results demonstrate that the test loss ${\cal L}$ exhibits a broken neural scaling law (BNSL) behavior as a function of the dataset size $N_D$. After passing through a random-guess regime, the loss follows architecture- and task-dependent scaling behavior. The loss crosses from a faster- to a slower-scaling branch, ${\cal L}\propto N_D^{-\alpha}$ and ${\cal L}\propto N_D^{-\beta}$ with $\alpha>\beta$ for image classification tasks. The exponents $\alpha$ and $\beta$ depend strongly on both the specific network architecture and the dataset-size regime, ranging from 0.4 to 1.5 and from 0.06 to 0.6, respectively. For the magnetic parameter-regression task, the loss follows a single scaling law with its exponent ranging from 1.28 to 2.59. Additionally, we provide a structural analysis of how activation functions refine their complexity as data volume increases, finding that dataset expansion drives a transition from simple linear-like approximations toward stable, interpretable symbolic forms. These findings provide a quantitative roadmap for the efficient application of KANs while managing the trade-off between model expressivity and computational overhead.
0
cs.LG Junke Wang, Hongshun Ling, Li Zhang et al. · Oct 1, 2026

HADRec targets two key gaps in AI-driven medication recommendation: drugs are usually treated as anonymous tokens, and predictions ignore the hierarchical structure of the ATC taxonomy. The proposed framework fuses LLaMA-7B–encoded clinical text with ChemBERTa molecular embeddings via cross-attention, then generates prescriptions through a four-level top-down ATC predictor constrained by a novel consistency loss. This is important because grounding recommendations in both chemical structure and medical ontology could improve accuracy, interpretability, and clinical trustworthiness.

Accurate medication recommendation is central to clinical decision-making, directly determining therapeutic efficacy and patient safety. However, existing methods suffer from two key limitations: drugs are often abstracted as discrete tokens, ignoring their molecular structures and pharmacological mechanisms, and the commonly used "flat" recommendation paradigm fails to leverage the hierarchical logic of the internationally standardized Anatomical Therapeutic Chemical (ATC) classification system. To address these issues, we propose HADRec, a Hierarchy-Aware Drug Recommendation framework that integrates molecular knowledge with electronic health records (EHRs). HADRec employs LLaMA-7B to encode clinical notes for rich patient representations and ChemBERTa to encode drug Simplified Molecular Input Line Entry System strings, building a global molecular knowledge base. A cross-attention mechanism then performs deep multimodal fusion between patient states and drug features. The framework further incorporates a hierarchical predictor and a novel consistency constraint loss to enforce strict adherence to ATC logical dependencies. Extensive experiments on MIMIC-III demonstrate that HADRec achieves state-of-the-art performance across Jaccard, F1, and PR-AUC. External validation on MIMIC-IV confirms strong generalization under distribution shifts, and calibration analysis shows well-calibrated predictive confidence on MIMIC-IV with ECE = 0.04, and Brier = 0.06. Counterfactual evaluation reveals clinically aligned reasoning, disentangling disease-specific treatments from general care. Together, these results establish HADRec as a high-performance, interpretable, and clinically grounded pathway toward safe and reliable AI-driven medication recommendation.
0
stat.MLcs.LG Taehyun Hwang, Hyunjun Choi, Heesang Ann et al. · Oct 1, 2026

This paper tackles endogenous nonstationary stochastic bandits where actions drive an unobserved latent linear system and rewards are bilinear in the action and latent state. Prior work achieved only $\widetilde{\mathcal{O}}(T^{2/3})$ regret via explore-then-commit (ETC) because the infinite-memory reward process couples learning and planning. The authors show that under stable dynamics the memory can be truncated geometrically, reduce the problem to a block-level linear bandit via cyclic approximation, and propose an optimistic block-UCB algorithm (Block-OFUL) that achieves $\widetilde{\mathcal{O}}(\sqrt{T})$ regret. The result is theoretically appealing but leans heavily on an exact block-maximization oracle and on knowing the dynamical stability constant $\rho$.

We study an endogenous nonstationary stochastic bandit problem with latent linear dynamics, where actions affect both immediate rewards and the future evolution of an unobserved latent state. Rewards are bilinear in the current action and latent state, inducing history-dependent rewards and a nontrivial long-horizon planning problem. The existing explore-then-commit approach achieves $\tilde{O}(T^{2/3})$ regret by uniformly exploring to estimate the latent dynamics and then committing to an optimized open-loop action sequence. We show that this rate can be improved via adaptive block-level optimism. Our key step is a cyclic approximation: under stable dynamics, the infinite-memory reward process can be truncated, and the open-loop benchmark can be approximated by optimizing a finite-memory block-level proxy. Building on this reduction, we propose a UCB-based block algorithm that maintains confidence sets for the truncated dynamics parameters and selects blocks optimistically. We prove a regret bound of order $\tilde{O}(\sqrt T)$, significantly improving over the previous $\tilde{O}(T^{2/3})$ guarantee for the same model. To the best of our knowledge, this is the first $\tilde{O}(\sqrt T)$ regret guarantee for latent linear-dynamics bandits with bilinear reward observations and an open-loop action-sequence benchmark.
0
cs.LG Hans Hao-Hsun Hsu, Minseon Gwak, Soon Hoe Lim et al. · Oct 1, 2026

Long-horizon probabilistic forecasting of dynamical systems is computationally demanding because traditional flow matching requires integrating along an auxiliary generative time axis. This paper proposes Variational Streaming Flow (VSF), which augments a physical-time velocity field with a single latent variable sampled once per rollout, enabling efficient multimodal forecasting with one network evaluation per step. VSF improves long-horizon accuracy and distributional fidelity on chaotic and stochastic systems and can plug into existing JEPA world models to boost planning success.

Probabilistic forecasting is important for predicting complex dynamical systems because intrinsic randomness and incomplete observations can cause the same observed state to evolve into multiple plausible futures. While flow matching is a flexible approach for probabilistic forecasting, it is computationally expensive. Streaming flow (SF) reformulates this approach to model temporal evolution efficiently by learning a continuous velocity field directly in physical time. However, SF learns a deterministic velocity field. Thus, it provides only a single future trajectory for a given fixed initial state and observation history. To overcome this limitation, we introduce Variational Streaming Flow (VSF). Our approach learns a latent distribution that is conditioned on the dynamics of interest. In turn, this enables probabilistic forecasting. Importantly, we retain the computational efficiency of SF by generating in physical time. Across deterministic and stochastic dynamical systems, VSF demonstrates superior predictive accuracy and distributional fidelity. We demonstrate the advantage for both long-horizon rollouts exceeding 1,000 steps, and settings with bifurcating dynamics. Moreover, VSF can be integrated into existing Joint-Embedding Predictive Architecture (JEPA)-based world models as a plug-and-play predictor to improve temporal dynamics and goal-directed success rate in navigation, motion planning, and manipulation.
0
cs.IRcs.CLcs.LG Chuxuan Hu, Hejie Cui, Norman Huang et al. · Oct 1, 2026

RPTune addresses product search for small merchants whose catalogs fit inside long-context LLMs. Rather than relying on retrieval pipelines, the authors show that feeding the full catalog works only when items are learned to be pruned, ranked, and positioned with downstream LLM feedback, after which the LLM itself is post-trained on these curated contexts using purely synthetic supervision. The result is a fully automated pipeline that achieves large accuracy gains and latency reductions across 7 merchants and 9 model families.

For small merchant businesses (SMBs) whose catalogs fit within a long-context LLM, full-catalog prompting offers a compelling alternative to multi-stage retrieval designed primarily for large marketplaces with millions of items. However, fitting the full catalog into the context window does not ensure that the model can use it effectively, since LLMs do not exploit long contexts uniformly. We therefore study in-context catalog search through two complementary questions: (1) how to curate and present catalogs to the LLM, and (2) how to adapt the LLM for product selection on curated contexts. We propose RPTune, an end-to-end framework that couples learned catalog curation with LLM post-training using automatically generated, catalog-grounded supervision. An encoder-reorganizer curator orders and prunes products guided by downstream LLM feedback, while the resulting curated catalogs in turn improve the effectiveness of LLM post-training with a context-relative reward. We evaluate RPTune on 7 real merchants spanning distinct retail verticals, using 100 complex conversational queries per merchant. RPTune consistently improves search accuracy across both proprietary and open-weight LLMs, with context curation yielding gains of up to 31.4 percentage points and post-training adding a further 10.3 points on average.
0
cs.DBcs.LG Abdalla Mohamed, Ashraf Aboulnaga · Oct 1, 2026

STEER attacks the high inference cost of relational foundation models by shrinking their graph-sampled context using schema semantics instead of random dropping. The approach prompts an LLM once per task to rank foreign-key edges into relevance tiers, then probabilistically steers neighborhood traversal during sampling. Evaluated on RelBench across three state-of-the-art RFMs, it cuts average context size by about 40% while maintaining or slightly improving accuracy, offering a practical, model-agnostic optimization.

Relational foundation models (RFMs) are pretrained once on a collection of relational databases and prediction tasks, and then applied zero-shot to previously unseen databases and tasks. To make a prediction for a target row, an RFM samples a neighborhood of rows linked to that row through foreign keys and uses this neighborhood as its inference context. Lowering inference cost is an important goal for any foundation model, and for RFMs this cost grows with the size of the context. The simplest ways to shrink the context is to drop some of the sampled rows, but this ignores the semantics of the database schema, so it is as likely to discard informative rows as uninformative ones. We propose STEER, a sampling approach that shrinks the inference context by concentrating it on the tables most relevant to the prediction task at hand. STEER obtains relevance information by prompting a large language model to rank the foreign-key edges of the database schema into relevance tiers for the given task, and then maps each tier to a probability of following that edge during traversal. Because the ranking uses only the schema, it is computed once per task and reused across all subsequent predictions, amortizing its cost. We evaluate STEER on three state-of-the-art RFMs (RT, RT-J, and Griffin) and show that it reduces inference context size by about 40% on average while maintaining, and in some cases improving, prediction accuracy.
0
cs.LG Zhanming Zhang, Vinoth Selvendran · Oct 1, 2026

Test-time reinforcement learning (TTRL) lets language models adapt on unlabeled problems using their own samples as supervision, but a diffuse initial policy wastes the limited adaptation budget concentrating probability mass instead of converting existing capability into reliable output. This paper proposes entry-state sharpening: use data-free training before TTRL to place the checkpoint in a concentrated state that subsequent label-free adaptation can exploit more efficiently. The core insight is that checkpoint preparation should be treated as a state-control problem—where entry entropy is a label-free readout and reachable capability is the constraint—rather than as a choice of upstream training recipe.

Test-time reinforcement learning (TTRL) adapts language models on unlabeled test problems using supervision derived from their own samples. This makes the checkpoint's \emph{entry state} consequential: a diffuse policy provides noisier self-supervision and may spend much of a limited adaptation budget merely concentrating probability mass before reliably expressing capability it already possesses. We propose \textbf{entry-state sharpening}: use data-free training \emph{before} TTRL to prepare a general-purpose checkpoint in a state that subsequent label-free adaptation can exploit more efficiently. The idea is not tied to one training recipe; different data-free objectives can move the same base model to different entry states. Across five data-free checkpoints derived from Qwen3-4B and evaluated under an identical 15-step TTRL protocol, entry policy entropy strongly rank-orders endpoint conversion efficiency, a reliability-to-reachability measure (Spearman $\rho=-0.90$; $\rho=-0.99$ after controlling for entry reachability). The contrast across objectives is striking: R-Zero remains diffuse at $3.39$ nats and finishes below the untuned base in 6/6 matched comparisons across MATH, GPQA, and AMC, whereas SPIRAL reaches $0.07$ nats and achieves the highest post-TTRL accuracy on MATH and GPQA despite its self-play stage using no math training data. An in-domain label-free self-distillation intervention further shows that the entry state can be deliberately sharpened. These results motivate treating checkpoint preparation as a \emph{state-control problem}: use data-free training to improve TTRL readiness, with entry entropy as a label-free control signal and reachable capability as the constraint.
0
cs.LG Ada Fang, Nikitha Thoduguli, Lukas Fesser et al. · Oct 1, 2026

Biological reasoning models fuse large language models with foundation-model representations and biological text to predict properties of DNA, proteins, and cells. This paper asks whether high benchmark accuracy actually reflects use of these biological inputs, or merely exploits overlapping text annotations. Through perturbation tests, evidence conflicts, linear probes, and reasoning-trace analysis across six models, the authors find that predictive representations are often ignored and that post-training gains can mask persistent over-reliance on text. The findings argue that evaluating input-specific reasoning must become standard alongside predictive accuracy.

Biological reasoning models use post-training to connect LLMs to biological foundation model representations and biological text. Their benchmark accuracy is taken as evidence that LLMs reason over these inputs. We test this assumption in six biological reasoning models across DNA, protein, and single-cell tasks. We perturb one biological input while holding the query and other inputs fixed, construct evidence conflicts that pair the foundation model representation of one genome, protein, or cell with the text of another, fit linear probes to the representations the language model receives, and analyze reasoning traces against the biological inputs. Evo2 and ESM3 contribute little to BioReason and BioReason-Pro performance on the evaluated tasks. Shuffling the DNA sequence barely changes BioReason disease prediction accuracy, and in evidence conflicts the two models follow the text in 97.9% and 99.7% of cases. Linear probes trained on the Evo2 and ESM3 representations predict the task targets, so these foundation models encode information relevant to the task, but provide limited overall performance improvement to BioReason and BioReason-Pro. In contrast, foundation model inputs contribute to ChatNT, Prot2Text-V2, and CellWhisperer performance, and differentially expressed genes in the gene sentence contribute to Cell2Sentence-Scale performance. Across SFT and RL checkpoints of BioReason-Pro and 42 BioReason checkpoints, increases in accuracy do not imply greater performance contributions from biological inputs. BioReason traces misstate nucleotide changes, while BioReason-Pro traces describe functions omitted from final predictions under evidence conflicts. We find that current post-training strategies do not ensure that foundation model representations contribute to task performance.
0
cs.LG Yair Schiff, Omer Belhasin, Roy Uziel et al. · Oct 1, 2026

Continuous diffusion language models have historically lacked two key features for practical deployment—variable-length generation and KV caching—while also trailing autoregressive and discrete diffusion in quality. This paper introduces Clock Diffusion, a framework that reparameterizes global diffusion time into position-dependent local clocks to enable semi-autoregressive denoising over token embeddings. Together with vectorized training masks and Cache Grab samplers, ClockDLMs close much of the perplexity gap on OpenWebText and unlock efficient inference, though downstream gains remain uneven across tasks.

Recent works on continuous diffusion for discrete data have demonstrated performance on par with comparable discrete diffusion models. However, these continuous counterparts lack key features that are essential to practical use as language models, namely variable-length generation and support for a key-value cache, and they still lag behind the frontier of autoregressive and discrete diffusion quality. In this work, we address these limitations. We do so by introducing a model parameterization that uses position-dependent noise schedules to define semi-autoregressive (SAR) continuous diffusion language models (DLMs). Together with efficient training and sampling algorithms, we call this framework Clock Diffusion, and we present two special cases of our method: block and sliding window generation. We then define ClockDLMs, a family of Gaussian DLMs based on sliding window Clock Diffusion that attain state-of-the-art diffusion likelihood bounds on OpenWebText, even beating the performant block SAR discrete diffusion models. ClockDLMs trained on TinyGSM also substantially outperform continuous baselines on the GSM8K benchmark and match and exceed comparable SAR discrete diffusion models. Finally, building on our parameterization, we propose more efficient samplers that we dub Cache Grab, which adapt techniques from accelerated inference in discrete diffusion, such as committing tokens whose probabilities exceed a confidence threshold and self-speculative decoding, further improving our models' quality and efficiency.
0
cs.CLcs.AIcs.LG Guangzhi Xiong, Zhenghao He, Bohan Liu et al. · Oct 1, 2026

In-context learning (ICL) lets LLMs adapt to new tasks from demonstrations, but reprocessing all examples for every query is costly and prior compression methods fail on complex, input-dependent tasks. This paper introduces Task Operator (TO), a training-free method that extracts per-head affine transformations — scaling weights and bias vectors — from the ICL forward pass and replays them during zero-shot inference by updating attention output projections. By treating the ICL effect as a dynamic, state-dependent modification rather than a fixed activation vector, TO substantially narrows the gap between zero-shot and few-shot performance while revealing sparse, task-specific circuits.

In-context learning (ICL) enables language models to perform new tasks from demonstrations without weight updates. However, every ICL inference requires processing the full set of examples, resulting in inefficient deployments, and how ICL works mechanistically is not fully understood. Prior work compresses ICL into fixed activation vectors extracted from specific layers or positions, but these input-independent interventions fail on complex tasks where the output depends on fine-grained interactions with the input. By analyzing the ICL forward pass, we show that each attention head's output is an affine transformation of its context-masked counterpart, and that the parameters of this transformation are empirically stable across samples for a given task. Building on this, we introduce Task Operator (TO), which replays this transformation as an analytically derived update to the attention output projection. Across lexical, algorithmic, and reasoning tasks, TO achieves the best overall performance among prior methods and substantially narrows the gap between zero-shot inference and ICL. We further show that the extracted knowledge concentrates in a task-specific sparse circuit across layers and positions, and that averaging operators from disjoint demonstration batches enables effective many-shot scaling without expanding the context window. Our code is available at https://github.com/gzxiong/task_operator.
0
cs.AIcs.CEcs.LG Aditya Dubey, Namah Gupta, Vinti Agarwal · Oct 1, 2026

This paper tackles the problem that LLM-generated economic policy can sound plausible yet be dynamically inconsistent. It grounds an instruction-tuned language model inside six DSGE simulators via a common RL interface, using PPO and GRPO to learn multi-turn policy actions with delayed rewards. The core idea is to replace linguistic plausibility with simulated economic consequences, testing credit assignment, semantic-shift conditioning, and cross-simulator transfer. Results matter for any setting where language agents must make sequential decisions with long-horizon structural feedback.

Large language models can produce economic policy responses that sound reasonable, but this does not show that their actions are consistent with economic dynamics. We test this by placing an instruction-tuned language model inside six Snowdrop-backed dynamic stochastic general equilibrium (DSGE) simulators. At each turn, the model observes the economy and a change in economic discourse, selects a bounded policy action, and receives the next simulated state and an economic reward. We implement a common Python interface for repeated rollouts, persistent shocks, state cloning, and rolling-horizon simulation. This setting creates a long-horizon credit-assignment problem. Policy effects may appear several quarters after an action is taken. PPO has a learned value function that can propagate delayed reward to earlier tokens through generalized advantage estimation. GRPO has no learned value function and instead assigns a group-relative advantage from complete rollout returns. It therefore cannot distinguish which earlier turn caused the outcome; if every rollout receives the same return, the normalized advantage is zero. We use PPO as the primary method and GRPO as a matched critic-free baseline. The experiments also test directional semantic signals, reward horizon, trajectory warm starts, cross-simulator transfer, and historically anchored pandemic and monetary-policy shocks. The objective is to judge policy actions by their simulated economic consequences rather than by plausible language alone.
0
cs.AIcs.LG Sharath M Shankaranarayana, Davor Runje, Jan Jannink · Oct 1, 2026

Decision models like Jev return probability distributions to drive routing, abstention, and human review, yet average calibration cannot distinguish whether uncertainty stems from chance or from missing knowledge. The authors audit this distinction in a black-box decision model through roughly 575,000 API calls across paired interventions that vary supplied information while holding items fixed, plus targeted follow-up questions about the case and the model’s own familiarity. Their core finding is that confidence tracks correctness on familiar material but fails at knowledge boundaries—assigning up to $p_{\max}=0.80$ to salient options with no basis and growing overconfident past an observed temporal boundary—while apparent self-knowledge largely evaporates once surface cues are controlled. The work matters because it provides a practical, behavioral checklist for black-box knowledge audits and shows that querying case properties directly can be more reliable than reading a single output distribution.

Decision models return probabilities intended for routing, abstention and automated action. Calibration makes those probabilities useful on average, but does not establish whether low confidence reflects chance or missing knowledge, nor whether confidence falls when a model moves beyond what it knows. We audit this distinction in Jev, a decision model, with over 15 public datasets and 6 generated task families, with paired interventions that vary the information supplied for a fixed item. Jev's confidence is calibrated on familiar closed-choice tasks but fails as an indicator of missing knowledge: with no answer-relevant information it assigns up to 0.80 to a salient option, and on news beyond an observed knowledge boundary it exceeds accuracy by 0.21--0.33, a gap that recalibration on earlier months does not close. Targeted yes/no questions give sharper readouts of the case: whether an outcome is settled (AUROC 1.00) and whether the evidence suffices (0.95, against 0.85 for confidence on the same items). Asking whether Jev knows the answer appears to flag fabricated entities and post-boundary news (0.91), but with realistic names or with dates removed it shows no advantage over answer uncertainty. Black-box knowledge audits therefore need explicit controls for surface cues. Code: https://github.com/Syntheme/beyond-answer-confidence.