Cryptography and Security · Cross-listed from quant-ph
Blind Unforgeability implies Plus-One Unforgeability
Mehil Agarwal, Calliope S. Reimann and Fang Song
We prove that
quantum blind-unforgeability implies
quantum plus-one unforgeability, settling an open question in the literature. Since plus-one unforgeability is known not to imply blind-unforgeability, our result establishes that blind-unforgeability is strictly stronger than plus-one unforgeability in the
quantum setting. The implication is proven using a new smoothing technique that coherently rescales the query histories of a
quantum-query
algorithm in a black-box manner. This enables us to transform any successful plus-one attacker into a blind-unforgeability attacker with only inverse-
polynomial loss. Our proof represents a conceptual shift from merely extracting a useful query history as in earlier attempts, which we show inevitably fails in general, to first coherently reshaping how query histories interfere.
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Machine Learning · Cross-listed from stat.ML
Fractional Laplace Neural Operators: Exact Architectures, an Expressivity Frontier at Criticality, and Certified Stability for Memory-Driven Network Dynamics
Mauricio Herrera-Marín
Neural operators learn maps between function spaces, while hereditary network dynamics are described by Volterra resolvents with non-rational Laplace symbols. We introduce a fractional Laplace neural operator (fLNO) that embeds this structure in the learned map. For commuting excitation–
Laplacian pairs, one block graph-spectral layer represents the full linear Volterra solution operator exactly. We establish an expressivity frontier for finite rational realizations: they approximate fractional
memory geometrically on compact frequency windows, but cannot reproduce the non-integer critical asymptotics generated by a branch point, and on the half-line the best rational rate is root-exponential. The same theory yields trainable parametrizations that enforce a prescribed stability margin by construction, and a graphon-transfer
theorem separates genuine operator consistency from parameter sharing. In a common-data
benchmark, positive rational operators can match or exceed fLNO accuracy on finite horizons, whereas in controlled near-critical experiments fLNO recovers the branching coordinate more faithfully with far fewer parameters; unconstrained rational fits can cross the stability boundary, while certified parametrizations cannot. A four-parameter spectral law transfers without retraining from graphs of size 48 to 192 with 0.51–0.62% relative error. Applications to Chilean aftershock sequences and to renewal models for Chile and 21 Italian regions illustrate structured inference with explicit uncertainty. The contribution is an operator-learning architecture in which exact
memory structure, physical coordinates and stability guarantees coexist with competitive accuracy.
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Artificial Intelligence
Before Agents Decide: Epistemic Action in LLM-Based Systems
Yizhi Liu, Balaji Padmanabhan and Siva Viswanathan
Before a difficult decision, people often act simply to understand the situation better. We turn an object to see another side, place alternatives next to each other, or change one condition and observe what happens. These actions may not complete the task, but they improve the evidence needed for the next choice. LLM-based
agents can search and explore, yet
agent design gives less
attention to an earlier question: is the available evidence ready for the decision? Sometimes necessary evidence is missing. In other cases, the evidence is present but its form hides what matters, or the comparison needed to judge it does not yet exist. Cognitive science calls actions that improve the basis for a later choice epistemic actions. We bring this idea to LLM-based
agents and distinguish three modes: acquiring missing evidence, transforming available evidence, and probing a system to create a revealing response. We use the term epistemic scaffolding for the interfaces, tools, and environments that make these actions possible and auditable. This paper argues that
agent design must address how decision-ready evidence is produced.
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Computational Complexity · Cross-listed from quant-ph
Noisy Quantum Query Complexity via Fractional Block Sensitivity
Mehil Agarwal, Shravas Rao and Fang Song
We study
quantum query complexity under several models of imperfect oracle access, and develop lower bounds through a common framework based on fractional block sensitivity ($\operatorname{fbs}$). For a negligent oracle that applies the correct query with probability $1-p$, we prove a lower bound in terms of $\operatorname{fbs}(f,0^n)$. We also show, perhaps surprisingly, that negligence need not destroy
quantum speedups: any function $f$ can be transformed into a partial function $f'$ whose negligent query complexity essentially preserves the
quantum query complexity of $f$. This gives partial functions with exponential
quantum speedups even under negligent queries, and in particular rules out a general lower bound in terms of $\operatorname{fbs}(f)$ for partial functions in this model. For two other models, we obtain general lower bounds in terms of $\operatorname{fbs}(f)$ for all Boolean functions. For hybrid
algorithms using $Q$ coherent and $C$ classical queries, we prove the tradeoff $C+Q^2=\Omega(\operatorname{fbs}(f))$. For an IID dephasing noisy model where each query dephases the query-index register at rate $p$ independently, we prove $\Omega\!\left(p\,\operatorname{fbs}(f)\right)$ queries are necessary. Finally, we introduce a broader family of time-varying dephasing models and identify a variational resource that is always lower bounded by $\operatorname{fbs}(f)$. Computing this resource reduces to a convex optimization problem, providing a simple way to derive lower bounds for new noise schedules. As applications, we recover the hybrid and IID dephasing bounds and determine the query complexity of unstructured search when the dephasing rate grows over time.
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Machine Learning
Denoising Surface: Modeling and Predicting Inference Cost for Diffusion LLM Serving
Haoyu Zheng, Fangcheng Fu, Binhang Yuan et al. (+6 more)
As
diffusion large
language models (dLLMs) become more capable, they are moving from research settings to real-world serving, where request management (such as scheduling and resource allocation) relies on accurate estimation of per-request inference cost. However, common cost proxies fall short for dLLMs: output length ignores that one forward pass can unmask multiple
tokens, and denoising-step count ignores the heterogeneous per-step costs. We observe that the block-autoregressive generation mechanism induces a two-dimensional execution structure over output blocks and within-block denoising steps, whereas these proxies collapse it into a scalar, discarding information essential for characterizing the cost. Motivated by this insight, we propose the Denoising Workload Surface (DWS), which preserves this two-dimensional block-step structure as a probability surface to weight the heterogeneous per-step costs. We then design a coarse-to-fine training scheme that enables a lightweight
prompt-only predictor to accurately predict the complex DWS. This predictor runs efficiently even on a single CPU core, avoiding GPU contention with the serving model. Since DWS decouples request-dependent execution behavior from deployment-specific cost factors, the predictor transfers across hardware configurations without retraining. In real-world serving experiments, DWS reduces cost-prediction error by up to $2.50\times$ over scalar-based predictors, while the DWS-guided shortest-job-first scheduler reduces end-to-end latency by up to $1.92\times$ for online chatbots.
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All authors Haoyu Zheng, Fangcheng Fu, Binhang Yuan, Yongqiang Zhang, Liang Deng, Hao Wang, Yuanyuan Zhu, Xiao Yan, Jiawei Jiang
Machine Learning · Cross-listed from stat.ME
Heteroskedastic Canonical Polyadic Tensor Decomposition
Kyle Ritscher and Carlos Llosa-Vite
When minimizing the squared-error loss, the popular CP decomposition can be interpreted as parameter inference in a Gaussian model with a low-rank mean tensor and constant variance across the tensor entries. We introduce heteroskedastic-CP (HCP), which models entrywise variability with a non-constant, low-rank precision tensor, and develop an alternating block-coordinate ascent method to recover both the low-rank mean and precision tensors from noisy observations. Our procedure is computationally competitive, with the same leading-order factor-update complexity as CP-ALS. We demonstrate HCP on synthetic experiments and an
EEG application.
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Machine Learning
Gumbel Straight Flow: Distilling Autoregressive Models into One-step Flow Maps
Yeongmin Kim, Arnaud Doucet, Andrew Campbell et al. (+3 more)
We present Gumbel Straight Flow (GSF), a continuous flow map
language model that leverages the noise-data coupling of a pretrained autoregressive
language (AR) model. We theoretically demonstrate that the coupling between Gumbel noise and one-hot
token sequences induced by an autoregressive model yields non-intersecting linear paths connecting the noise to the sequence representations. To further enhance high-quality few-step path sampling, we use a flow map
semigroup objective where the tangent (velocity) condition is guided directly by the AR teacher. Across various
benchmarks, including pretraining and downstream tasks, GSF can outperform current few-step
language generation baselines.
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All authors Yeongmin Kim, Arnaud Doucet, Andrew Campbell, Valentin De Bortoli, Thomas Mensink, David Ruhe
Machine Learning
Score the Update, Not the Token: Descent-Aligned Routing for Combinatorial LoRA Experts
Priya Nair, Lukas Brenner, Maya Lindqvist et al. (+5 more)
Mixture-of-LoRA-experts methods raise the capacity of low-rank adaptation by routing each
token to a few low-rank experts. Nearly all of them tie one input-side factor to one output-side factor per expert, and nearly all of them route by scoring the
token: the router picks experts without seeing what any of them would write. We argue that the router should score the update. To first order, adding an expert's update to a layer output lowers the loss by the inner product between that update and the negative loss gradient at the output. This usefulness is quadratic in the
token, so a router that is linear in the
token sees only the part of it that runs through the
token mean, and routers that rank experts by the norm of their own activations never see the output factor. If each expert is split into a reader (down-projection) and a writer (up-projection), the usefulness of every reader–writer pair becomes an inner product in the shared rank-$r$ space, and all $N_AN_B$ pairs can be scored from $N_A+N_B$ vectors. We build VANE on this identity. A low-rank compass predicts the descent direction of each
token. VANE scores every pair by the
alignment between its update and the compass without forming any update, activates the top-$k$ pairs with additive gates, and gives every pair its exact first-order router gradient. On single-domain commonsense
reasoning and a four-domain multi-task mixture with Llama-3.2-3B and Llama-3.1-8B, VANE attains the best average among twelve PEFT and MoE-LoRA baselines, by 0.9–1.1 and 1.3–1.5 points respectively, with less than half the trainable parameters of an 8-expert MoE-LoRA. Its router scores also track the measured usefulness of experts far more closely than
token routers do.
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All authors Priya Nair, Lukas Brenner, Maya Lindqvist, Daniel Whitmore, Wen-Hsuan Liu, Tom Saliencro, Amara Okonkwo, Rohan Desai
Computation and Language
EurekaBench: Measuring Agentic Ability to Discover New Scientific Insights
Jiayi Geng, Zhengxuan Wu, Kevin S. Chen et al. (+12 more)
When Isaac Newton discovered the law of gravitation, he did so through an iterative process of analyzing observed data such as planetary patterns, finding the underlying mechanisms by describing patterns in mathematical equations, and refining his theory against the Moon's orbit, revealing the startling insight that the same force governs both falling apples and orbiting
planets. Would it be possible for AI
agents to make similar discoveries? To measure this ability, we introduce EurekaBench, a cross-domain
benchmark that tests AI
agents' ability to conduct long-horizon experiments and discover mechanisms that explain observations. We evaluate these mechanisms by the scientific insights that can be derived from them. EurekaBench contains an expert-verified set of 26 long-horizon tasks across neuroscience, computer science, chemistry, astrophysics, geophysics, and
plasma physics, with a total of 306 scientific insights that the discovered mechanisms are expected to support. Our evaluation framework tests three axes of scientific discovery:
agents' ability to follow known scientific constraints, the predictive accuracy of the discovered mechanisms, and whether these mechanisms yield scientific insights or inform future research. Our results show that current AI
agents often overly fixate on predictive accuracy optimization, surpassing human scientists, while falling substantially short in deriving scientific insights.
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All authors Jiayi Geng, Zhengxuan Wu, Kevin S. Chen, Seungone Kim, Joseph Janssen, Zora Zhiruo Wang, Bhupalee Kalita, Runtian Gao, Aaron Ho, Andrew Oakleigh Nelson, Olexandr Isayev, Francisco Villaescusa-Navarro, Ching-Yao Lai, Howard Chen, Graham Neubig
Data Structures and Algorithms
Dynamic Connectivity, Minimum Spanning Tree, and 2-Edge Connectivity with Polylogarithmic Worst-Case Update Time
Simon Meierhans, Maximilian Probst Gutenberg and Yu-Cheng Yeh
We give fully dynamic
algorithms for maintaining connectivity, minimum spanning tree, and $2$-edge connectivity of a graph with worst-case polylogarithmic update time. Our
algorithms are randomized and succeed with high probability against an adaptive adversary. For the minimum spanning tree and $2$-edge connectivity problems, this improves over the subpolynomial update time bounds obtained by Nanongkai, Saranurak, and Wulff-Nilsen [FOCS'17], Jin and Sun [FOCS'21], and Jin, Sun, and Thorup [SODA'24], respectively. The only randomized component of our
algorithms is the computation of static expander decompositions, and a deterministic
algorithm for said problem would directly imply deterministic
algorithms for all three problems. This reduction is novel even for the connectivity problem.
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Robotics
ScaffoldM3C: A Multimodal Sequential Monte Carlo Framework for Generative Stable Construction Planning
Gadiel Sznaier Camps, Chengyang He, Guillaume Sartoretti et al. (+2 more)
Autonomously constructing physically realizable 3D structures remains a significant challenge due to combinatorial action spaces, interchangeable components, equifinal assembly sequences, and strict stability requirements during construction. State-of-the-art methods fine-tune large
language models for text-based generative construction. However, these approaches do not allow for
Multimodal (text, image, sketch) conditioning, overlook the practical role of scaffolding for stabilizing intermediate structures, and suffer from slow inference speeds. Therefore, we formulate construction as a probabilistic next-block generation task with multiple potential assembly actions and multiple potential task conditioning modalities. Concurrently, we explicitly consider the utility of scaffolding by introducing an auxiliary scaffold block
token. We present Scaffold
Multimodal Monte Carlo (ScaffoldM3C), a
multimodal, lightweight, auto-regressive model for stable block-based construction, that proposes a set of next-step candidate blocks. Leveraging these candidates, we utilize Sequential Monte Carlo (SMC) to maintain a population of possible assembly sequences, allowing us to consider multiple, potentially different, assembly directions simultaneously. We train our
multimodal architecture by extending the StableText2Brick
dataset to contain image conditioning
prompts and scaffold-stabilized build sequences. ScaffoldM3C is 4x smaller than competing baselines, yielding a 5x to 20x speedup during inference, while achieving comparable construction quality to state-of-the-art methods and higher overall stability. We demonstrate the effectiveness of our approach through simulations and real-world
robot assembly demonstrations.
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All authors Gadiel Sznaier Camps, Chengyang He, Guillaume Sartoretti, Eduardo Montijano, Mac Schwager
Computer Vision
PixelDense: Dense Prediction as Representation Alignment for Pixel Diffusion
Lehan Yang, Daiqing Qi, Wenhao Zhang et al. (+9 more)
Representation
alignment (REPA) accelerates
diffusion transformer training, but its
alignment targets are almost exclusively semantic encoders such as DINOv2 and CLIP. Recent analysis points to spatial structure, not global semantics, as the carrier of the
alignment effect, yet dense-prediction foundation models trained to predict that structure remain overlooked as REPA targets. In pixel-space
diffusion, SAM2, Depth Anything v2, and Metric3D v2 each outperform the DINOv2-only GenEval baseline, with the two
geometric teachers leading the
segmentation teacher. A flat sum of all four teachers, however, lands below the best single
geometric teacher, as semantic and
geometric gradients compete for one denoiser projection. We introduce PixelDense, which routes DINOv2 and SAM2 through a semantic projection stream, routes Depth Anything v2 and Metric3D v2 through a
geometric projection stream, and adds a weight-space orthogonality penalty that keeps the two streams in disjoint subspaces. All four teachers are frozen during training and dropped at inference. Applied to PixelGen and DeCo with a single recipe, PixelDense improves GenEval, DPG-Bench, and HPS v2.1, raises PixelGen-XXL's GenEval Overall from 0.7927 to 0.8093, and beats every single-teacher and unfactored multi-teacher variant. In partial-noise reconstruction, independent panoptic, depth, and surface-normal probes show up to 53.1% PQ gain and 36.0% depth AbsRel reduction at $\tau=0.5$ across COCO and Flickr30K. From random initialization, PixelDense also reaches the baseline's peak GenEval 1.23x faster. In SDEdit editing on PIE-Bench, PixelDense keeps more of the source background and layout at every edit strength, raising background PSNR by up to 2.2 dB.
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All authors Lehan Yang, Daiqing Qi, Wenhao Zhang, Avery Li, Yiqing Yang, Yifan Li, Yu Kong, Haitian Zheng, Zhifei Zhang, Zhe Lin, Varun Jampani, Sheng Li
Information Theory
AIR-LLM: Broadcasting AI Weights over Radio for Memory-Free Edge LLM Inference via RF Computing
Zhihui Gao, Tingjun Chen and Dirk Englund
Next-generation large
language models (LLMs) are expanding from the cloud to ubiquitous edge devices. However, edge devices typically either lack the
memory to store increasingly large LLM weights or, even with enough
memory, spend unaffordable energy on loading the weights. This raises our question: can an edge device run an LLM without storing or loading its weights, but receive them over the air and consume them on the fly? Inspired by wireless broadcasting, we present AIR-LLM, an LLM inference architecture for edge devices, which is composed of: (i) a central
radio (e.g., 5G base stations) that broadcasts the LLM weights into the air, and (ii) the edge user that receives the weights and completes the general
matrix-vector multiplication (GEMV) of LLM inference directly in the
radio frequency (RF) domain using RF mixers. To further shorten the airtime, AIR-LLM exploits
MIMO spatial multiplexing and proposes an energy-efficient precoder-postcoder pair on the edge to calibrate its own wireless channel. Since the central
radio stays user-unaware, AIR-LLM is user-scalable so that one broadcast serves unlimited users within its coverage. We implement AIR-LLM on the NVIDIA Sionna ray-traced channels of two real-world urban scenes and the profiling of a real RF mixer. With a WikiText-2 perplexity degradation of 4.0% on LLaMA-3.1-8B, AIR-LLM saves the energy by 157.7x/40.4x against the FP16 and weight-only quantization baselines; with 20 users, its airtime is 104.1x/26.0x shorter, respectively.
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Computer Vision
PACT: End-to-End Learning of Human Pose, Contacts, and Forces from Video
Rikhat Akizhanov, Yangsong Zhang, Nikolai Kaliazin et al. (+5 more)
Human motion, environmental contacts, and interaction forces are governed by common physical laws, yet existing approaches typically separate visual pose reconstruction from contact and force estimation. This separation limits joint
reasoning and can propagate errors between stages. We introduce PACT, an end-to-end model that jointly learns to estimate human pose, contacts and contact forces from
monocular video. Our approach augments a human reconstruction foundation model with learnable contact-force
tokens and a temporal
transformer that integrates visual features with world-space motion. Joint prediction heads refine human poses and estimate contacts and forces, while physics-based supervision encourages consistency between the reconstructed motion and interaction forces. To address the scarcity of force annotations, we develop a data annotation pipeline that combines contact labeling with physics-based motion and force optimization, producing training supervision from synthetic and real-world
videos. We also introduce a real-world climbing
benchmark ForceWall with climbing
videos and corresponding ground-truth contact forces obtained from the force sensors. Experiments demonstrate state-of-the-art contact and force estimation, outperforming staged reconstruction approaches and generalizing to interactions beyond the training distribution. These results support end-to-end joint learning as an effective approach to recovering human motion and physical interactions from
video.
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All authors Rikhat Akizhanov, Yangsong Zhang, Nikolai Kaliazin, Peter Wolf, Yoshihiko Nakamura, Pascal Fua, Fabio Pizzati, Ivan Laptev
Cryptography and Security
ZoneClaw: Mitigating Persistent Memory Attacks by Establishing Memory-Zoning in OpenClaw-Style Computer-Use Agents
Haokai Ma, Chieh Lin, Yupeng Qiu et al. (+1 more)
Computer-use
agents increasingly operate as long-running assistants through persistent workspace
memory, which OpenClaw-style CUAs realize as automatically reloaded files that hold user instructions, system summaries, and external claims at the same privilege level. Here, remembering a claim confers authority over later behavior. This enables a persistent
memory attack, in which an attacker who controls only benign-looking external content induces the CUA to record attacker-favored claims during a legitimate task, and those claims later govern benign tasks the attacker never touches. The attack chain extends "malicious context -> malicious response" into "malicious context ->
memory injection -> malicious execution", making this a cross-environment threat. Existing defenses studied intervene either before content enters
memory or at the action it later induces, not whether stored content may guide action. We propose ZoneClaw, which separates persistence from authority by replacing flat workspace
memory with hierarchical trust zones carrying explicit authority levels. External claims persist in a low-trust zone and acquire action-guiding authority only by crossing an explicit authority boundary, at which promotion is cross-checked against zones the attacker cannot directly write. Role-specific processes of asymmetric privilege enforce this boundary, ensuring that no process both ingests external content and acts outward. Across four attack scenarios, two injection settings, and four backbones, ZoneClaw drives ASR from 372/480 to 6/480 while retaining utility in 458/480 trials, and remains effective against some defense-aware attackers. Attacker claims still persist in low-trust
memory yet rarely cross the authority boundary, showing that ZoneClaw withholds authority rather than refusing to learn from the environment. Our code is available at: https://github.com/euph00/ZoneClaw-code.
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All authors Haokai Ma, Chieh Lin, Yupeng Qiu, Ee-Chien Chang
Information Theory · Cross-listed from quant-ph
Learning Local Fermionic Lindbladians under Parity Superselection
Tim Möbus, Daniel Stilck França and Cambyse Rouzé
Parity superselection forbids direct measurement of odd Majorana observables. We learn time-independent, parity-covariant, $k$-mode-local Lindbladians on $m$ modes using even preparations and measurements with uninterrupted short-time
evolution. Internal markers turn odd probes into even observables, and pair measurements among three separated markers calibrate their dynamical contributions. Signed Fierz inversion recovers canonical coefficients, while semidefinite fitting yields a valid generator. For finite-range models on known bounded-degree graphs with suitable marker access and a supplied weighted-strength bound $\bar\alpha$, entrywise error $\varepsilon$ is achieved using $\widetilde{\mathcal{O}}(\bar\alpha^2\varepsilon^{-2}\log(m/\delta))$ samples, without external modes or known nonzero coefficient locations. Recovery to diamond-norm error $\varepsilon$ costs an additional factor $m^2$, matching lower bounds for short-time experiments on fresh systems up to logarithmic and fixed
geometric factors. Without a supplied graph, one idle ancillary mode per system mode and potentially nonlocal pair operations give total absolute coefficient error at most $\varepsilon$ per mode using $\widetilde{\mathcal{O}}_k(\bar\alpha^2\mathsf d^2m^{\lfloor k/2\rfloor}\varepsilon^{-2}\log(m/\delta))$ samples, under a supplied approximate coefficient-degree bound $\mathsf d$ and controlled weak-coefficient tails. All guarantees hold with probability at least $1-\delta$. For
geometric models, fixed-support even observables can be predicted with logarithmic system-size sample complexity at fixed time and accuracy. We also give finite-volume and exponential-tail extensions.
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Artificial Intelligence
Frozen Scenes, Shifting Winners: Configuration Fragility in Text-to-3D Evaluation
Anson Y. Lam, Shuqing Li and Michael R. Lyu
Can a text-to-3D leaderboard change when every generated scene stays fixed? We audit this question for rendered-image evaluation, where camera settings and caption wording become part of the measurement protocol. Across 300 frozen scenes from six generators, we vary eight render and caption factors for 19
alignment evaluators plus one perceptual-quality control, then test four targeted scene degradations. Peak configuration variance exceeds between-generator variance for 17/19
alignment evaluators, with
prompt-bootstrap lower bounds above 1 for 11/19. Rankings are more stable than scores, yet 18/19 evaluators change their point-estimate winner under some configuration. Pairwise protocol margin envelopes show which comparisons keep their direction across the tested settings. Selected pairs have opposite pointwise intervals, but no reversal survives simultaneous inference over the full search. Thus the observed winner changes are descriptive, not confirmed changes in generator superiority. Sensitivity remains separate: no evaluator, even the
prompt-free control, exceeds 67% tie-adjusted directional discrimination on layout scrambling, which is diagnostic rather than human-validated ground truth. The audit separates score stability, decision uncertainty, and targeted sensitivity, and recommends reporting (generator, score, card ID) with protocol-dependent comparisons and selection-aware uncertainty.
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Machine Learning
Exact information accounting for SGD methods
Akshay Balsubramani
As an alternative to the standard
geometric analyses, we give an exact, information-theoretic analysis of
stochastic gradient descent (SGD) and its variants. We show that a preconditioned SGD step is the posterior-mean update of a Gaussian Bayes model, and that its one-step regret splits into an intrinsic-time cost and a change in comparator information. The split extends to an identity for the objective itself. Convex convergence, strict-saddle-point escape, the link between flatness and generalization, the standard learning-rate schedules, adaptive optimizers, and the noisy, momentum, heavy-tailed, and gradient-free variants of SGD each correspond to a term or a special case of this identity. We measure its terms on synthetic and real training runs. On real networks it attributes the slack of classical convergence bounds to the terms their derivations drop and separates optimizers that reach the same training loss. That separation follows the number and consistency of their steps. Its relation to which of them generalizes better differs between networks. For gradient-free SGD the identity determines how a
curvature preconditioner should enter the update. The sharpness-based generalization certificate it yields, with a data-independent isotropic prior, is vacuous at network scale unless the
curvature spectrum is nearly flat across all parameters.
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Machine Learning
One pool, many targets: a conservation layer and what archival data can identify
Zahra Khodagholi and Niloofar Yousefi
Pairwise guide–transcript scores do not enforce conservation of a finite guide-loaded RISC pool when they are interpreted independently as occupancies. We formulate a differentiable scalar
equilibrium layer: one conservation equation with a unique positive root and exact implicit gradients. It yields a redistribution
theorem, a qualified high-resource limit, an analysis of the
retrieval approximation, and a conditional rank-invariance result: within one construct at one dose, rankings by fractional occupancy cannot distinguish
equilibrium from independent scoring. We therefore audit the two experiments that proposition leaves open, dose and cross-context, on archival off-target data. Corrected thermodynamic affinities associate weakly with measured repression in the direction a working predictor requires, but a paired permutation test and a construct-cluster bootstrap do not establish added predictive value from the coupling: what survives their differing permutation-null baselines is \GapNet{}, a descriptive \GapNetOverSE{} of the
equilibrium association's cluster standard error. The dose fits are heterogeneous and frequently violate the model-implied exponent constraint, which is superlinear rather than sublinear, so these data do not identify the competition parameter. A saturable compression of the competitor set holds both accuracy targets on held-out guide families but is not faster at the size measured. The contribution is a reusable conservation operator and the experimental information needed to test it. The code for this study is available at https://github.com/shadi97kh/One-Pool-Many-Targets.
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Cryptography and Security · Cross-listed from quant-ph
Quantum Secret Sharing and Error Correction vs No-Cloning
Steven Chien, Ishani Mukherjee and Mark Zhandry
Secret sharing is ubiquitous throughout cryptography. All possible access structures are classically feasible, and in the case of threshold access structures, the protocols are even very efficient. However, when moving to the
quantum setting, the no-cloning
theorem shows that many access structures are impossible. In fact, no-cloning exactly characterizes feasibility: for thresholds,
quantum secret sharing is possible if and only if the threshold $t$ is strictly more than $n/2$. In this work, we propose a variant of
quantum secret sharing (QSS) where two or more identical copies of the input state are provided, but the output is only required to recover one copy. This notion circumvents the simple one-copy no-cloning obstruction, though the natural $k$-copy generalization still gives much milder obstructions. For thresholds using $k$ copies, no-cloning implies that QSS is impossible whenever $t\leq n/(k+1)$. It is tempting to hypothesize that no-cloning continues to exactly characterize the many-copy case. However, we show that this is not the case. We give positive results showing that multiple copies allow for going slightly beyond the single-copy obstruction: for thresholds, we construct QSS whenever $t>(n-k+1)/2$. On the other hand, we give a novel obstruction we call the Clique Path obstruction, which applies to arbitrary access structures. For thresholds, it shows that QSS is impossible whenever $t\leq (n-1)/k$. Our upper and lower bounds exactly match for $k=2$. Both our results leverage connections to the $k$-colorability of certain graphs derived from the access structure. We leave closing the gap for $k\geq 3$ copies as a fascinating direction for future work. Secret sharing is closely related to error correction, which can also be considered in the many-copy setting. Our results imply similar obstructions for
quantum error correction for erasure channels.
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Information Theory · Cross-listed from quant-ph
Finite-blocklength classical communication over the quantum erasure channel with and without classical feedback
Mark M. Wilde
We determine the optimal success probability for transmitting a fixed number of classical messages through a finite number of uses of the
quantum erasure channel, assisted by noiseless classical feedback and without initial shared
entanglement. For an input dimension $d$, an erasure probability $p$, a blocklength $n$, and $M$ equiprobable messages, the optimal success probability is equal to $E[\min\{1,d^K/M\}]$, where $K$ is binomial with parameters $n$ and $1-p$. The converse allows arbitrary adaptive
quantum encoders,
quantum memories, and receiver instruments. Its main ingredient is an elementary dimension bound for noiseless
quantum communication with classical feedback, proved by fixing the classical controls without conditioning the sender's state on the observed transcript. A classical protocol that transmits the base-$d$ digits of an integer representing the message, repeating each digit until the receiver acknowledges its reception or the prescribed blocklength is reached, attains the bound for every integer $M$. We also establish a relative-majorization property of erasure-channel outputs and exactly evaluate a hypothesis-testing converse, recovering the same numerical bound without feedback. That converse need not be achievable without feedback: four uses of the
qubit erasure channel and four messages give a strict gap. A product-state code employing tetrahedral
qubit states nevertheless outperforms every classical binary erasure code with these parameters. We give an explicit message-size formula and show that the bounded-remainder normal approximation and the average-success strong-converse exponent are unchanged without feedback. We also determine the feedback-assisted error exponent below capacity, prove that it agrees with the no-feedback exponent above a critical rate, and give no-feedback bounds at lower rates.
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Robotics
Towards a General Humanoid Loco-Manipulation Model via Egocentric Whole-Body Human Data Pretraining
Chongyang Xu, Zhao Wu, Jin Chen et al. (+9 more)
Humanoid whole-body manipulation has advanced rapidly, enabling policies to coordinate locomotion, posture, bimanual interaction, and dexterous hand movements. Meanwhile,
egocentric human
videos provide diverse examples of everyday interactions across objects and scenes, offering scalable supervision without
robot operation. However, existing supervision from these
videos provides limited coverage of whole-body movement and coordination with hand-object interaction, while obtaining such supervision through
humanoid teleoperation is also costly and difficult to scale. We therefore explore how human experience can support scalable learning of
humanoid loco-manipulation. To support this study, we introduce HumanVerse-500, a 500-hour
dataset of diverse human loco-manipulation behaviors in open-world environments, collected with a lightweight wearable system that synchronizes
egocentric video with body and hand motion. Building on this
dataset, we develop $\lambda_0$, a whole-body
humanoid vision-
language-action policy, through three-stage training that first learns interaction from diverse
egocentric datasets, then coordinates body and hand motion using HumanVerse-500, and finally adapts the policy to downstream tasks and
robot embodiments. Across these stages, $\lambda_0$ learns a shared representation space for human experience transfer, while domain-specific interfaces handle differences between human and
robot states and actions. We evaluate $\lambda_0$ on SIMPLE and 4 real-world loco-manipulation tasks, achieving state-of-the-art performance, and further analyze its scaling behavior, generalization, and training-stage contributions to understand how human data support downstream whole-body
humanoid control. We will release our code, models, and data to support further research.
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All authors Chongyang Xu, Zhao Wu, Jin Chen, Yiming Jiang, Jinhui Ye, Yuming Jiang, Shifeng Zhang, Ziliang Feng, Mu Xu, Yilun Chen, Li Lu, Steven C.H. Hoi
Artificial Intelligence
JevSpawn: Adaptive Agentic Inference through Compositional Action Spaces
Haoyang Su and Weiran Huang
LLM
agents generate intermediate
reasoning and actions
token by
token, making extended interactions slow and computationally expensive. Jev-style models offer fast probabilistic predictions over finite fields, but require those fields to be specified in advance. This requirement limits autonomous task solving, where the available actions must be derived from natural
language instructions and adapted through interaction. We introduce JevSpawn, a compositional policy that connects natural
language task specifications to finite probabilistic exploration. Parallel action spawning is coupled with feedback driven branch selection, representation revision, and recovery from retained alternatives. Shared action structure and model prefixes reduce repeated generation and context computation without additional training. Evaluations on eight
benchmark tasks against seven
agent baselines and a TypeSafe Jev variant establish JevSpawn as a promising approach to structured agentic inference, with improved task performance and faster
navigation.
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Machine Learning
Every Batch Is Its Own Validation Set: Leave-One-Out Gradient Matching for Online Data Selection in LLM Fine-Tuning
Hongyu Chen, Xinyi Luo, Ming Zhao et al. (+6 more)
Online batch selection fine-tunes a
language model on the most useful part of each candidate batch. Selectors that match the gradient of the candidate batch are attractive because they need no held-out data, yet they rarely beat training on the whole batch. We show why. In-sample gradient matching uses every example as part of its own target, so its objective credits each example with its own gradient noise. This is the covariance penalty that makes training error optimistic, now sitting on the diagonal of the gradient Gram
matrix: it steers selection toward the noisiest examples and makes the full batch the best solution the objective can reach. The fix costs nothing. For each example, the other candidates form an independent sample of the data distribution, so removing the diagonal turns the matching objective into an unbiased estimate of the update's error with respect to the population gradient. The minimizer of this leave-one-out objective weights examples by their gradient signal-to-noise ratio (SNR), and whenever per-example SNR is heterogeneous enough, half of a batch yields a lower-error update than the whole batch; we give the exact condition. We build \method{} on this principle. It computes the Gram
matrix in the metric of the Adam preconditioner during the ordinary backward pass, selects a weighted subset greedily with a $(1-e^{-\gamma})$ guarantee, and uses no held-out data. Across four fine-tuning tasks and seven backbones from 1.5B to 8B parameters, LOOM improves on full-batch training by 2.3 and 2.4 points on Llama-3.1-8B and Qwen2.5-7B, exceeds every in-sample gradient matcher by 2.4 points and the validation-guided GREATS and OPUS by 1.6–2.0, and selects injected label noise at under a fifth of its base rate.
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All authors Hongyu Chen, Xinyi Luo, Ming Zhao, Lin Tang, Zihan Xu, Jing Li, Yuxuan Wang, Haoran Deng, Wei Zhang
Artificial Intelligence · Cross-listed from hep-th
How AI Agents Discover Scientific Equations: From Hydrotope Rediscovery to New Water-Wave Amplitudes
Zihan Zhou, Digvijay Wadekar and Matias Zaldarriaga
We study how AI
agents discover and validate scientific formulas using a controlled case study of the hydrotope, a recently discovered
geometric formula that combines the different
polynomial pieces of nonlinear surface-wave scattering into one global expression. This problem is deceptively difficult: simple formulas can hold within individual frequency regions, but the global result must identify their boundaries and combine exponentially many potentially active terms. We reconstruct how the formula was originally discovered through human–
agent collaboration and analyze 18 single-
prompt rediscovery runs under no hint and two forms of human guidance: a false hint representing an incorrect prior and a true hint representing domain-informed insight. Only four recover the formula across all kinematic chambers (i.e., regions in which a single
polynomial form applies), while most unsuccessful runs find correct chamber
polynomials but fail to combine them or test their full domain. Conventional and LLM-assisted symbolic regression and standard machine-learning regressors likewise fail to recover the global formula in our experiments. Guided by these failure modes, we test a PI$+$two-student workflow in which a coordinating lead
agent assigns complementary analytic and numerical tasks to two research
agents and independently evaluates their results. The PI$+$two-student team successfully rediscovers the complete hydrotope formula, while the same workflow applied to the harder three negative wavenumber problem discovers a new independent verified analytic expression for the six-point amplitude $A_6$.
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Machine Learning
XOR-Trellis: Ultra-Low-Complexity Dequantization and Curvature-Aware Hadamard-Free LLM Quantization
Xiaofan Que, Nir Elkayam, Spandan Pyakurel et al. (+2 more)
Trellis-coded quantization enables high-dimensional compression of large
language model (LLM) weights at ultra-low bit widths without the exponentially large codebooks required by conventional vector quantization. Practical deployment, however, presents two challenges: reconstructing compressed weights at sufficient parallel throughput to avoid making dequantization an inference bottleneck, and maintaining quantization accuracy without costly incoherence transformations. We address these challenges with two complementary techniques. First, we introduce an ultra-low-complexity trellis dequantizer that uses a structured, hardware-efficient state-to-value mapping while preserving diverse reconstruction choices for trellis search. Second, we reformulate discrete trellis path optimization with a
curvature-aware objective that reflects model sensitivity directly in the original coordinate space. Together, these techniques enable high-quality ultra-low-bit trellis quantization with inexpensive, highly parallel runtime reconstruction and without relying on Hadamard-based incoherence processing.
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All authors Xiaofan Que, Nir Elkayam, Spandan Pyakurel, Shuokai Pan, Dibakar Gope
Machine Learning · Cross-listed from stat.ML
ChainLoRA: Geometry-Preserving Task Vector Merging for Continual Learning in LLMs
Hang Yin, Haozhe Wang, Yuhua Luo et al. (+3 more)
Continual parameter-efficient fine-tuning for large
language models (LLMs) must balance retention of previously acquired knowledge, adaptation to new tasks, and strict parameter budgets. We present ChainLoRA, a replay-free continual merging framework built on chain-updated task-vector geometry. From a parameter-merging perspective, we formulate a
geometric view of forgetting through a measurable interaction between task updates, separating directional overlap from coefficient coupling. Building on this view, ChainLoRA combines chain-updated training with post-stream adaptive SVD merging. During training, initialization and a one-sided orthogonality proxy use only the last carrier, keeping their historical-state footprint and regularization overhead constant as the task stream grows. At merging time, Adaptive SVD extracts a shared carrier and aligns it to the latest task through Procrustes adaptation. Our theoretical analysis shows that Procrustes adaptation facilitates
geometric approximate separation of shared and task-specific components. The one-sided proxy further bounds inter-task interference. An effective-rank penalty additionally promotes efficient utilization of the task subspace during continual learning. Experiments show that ChainLoRA achieves state-of-the-art performance among the evaluated replay-free methods on the Large and SuperNI
benchmarks, while remaining competitive on Standard CL and attaining almost the closest average scores to the evaluated replay-based method across all three
benchmarks.
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All authors Hang Yin, Haozhe Wang, Yuhua Luo, Zhangqi Pan, Xiaoxing Wang, Junchi Yan
Social and Information Networks
Memetic Trojans: Social Contagions as Carriers of Adversarial Payloads in Agent Networks
Birk Torpmann-Hagen, Finn Schwall and Leon Moonen
Autonomous large
language model (LLM)
agents increasingly interact in network environments where
adversarial content can propagate between
agents. Known attacks include
agent worms, which spread through self-replicating
prompt injections or configuration compromises. We introduce memetic trojans, a distinct class of network-mediated attack that exploits
agents' tendencies to retransmit and amplify content. Unlike
agent worms, whose propagation is adversarially induced, memetic trojans exploit endogenous transmission by
embedding adversarial payloads in social contagions: content
agents have internal reasons to share. As part of our work, we extract social contagions from Moltbook, a social media platform for LLM
agents. Controlled transmission experiments reveal large differences in virality: the most effective contagion is retransmitted in approximately 50% of subsequent
agent posts and upvoted at 2.5x the average post's rate. Its memetic trojan counterpart largely inherits these properties. Monte Carlo attack simulations show that memetic trojans amplify expected exposure by up to 3.19x. Network structure and amplification mechanisms strongly shape propagation, producing heavy-tailed outcomes with near network-wide exposure. These results identify endogenous social transmission as a distinct security vulnerability in multi-
agent systems. Because propagation does not require
agents to follow malicious retransmission instructions, defenses focused on
prompt-injection detection or preventing
agent compromise cannot alone prevent memetic trojan propagation. Securing large-scale
agent ecosystems may require network-level defenses that account for how
agent preferences, recommendation mechanisms, and network
topology amplify
adversarial payloads.
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Information Theory
Modulation Augmentation and Constellation Shaping for LDPC-Coded QPSK
Heping Wan, Joonyoung Cho, Sandesh Rao Mattu et al. (+4 more)
While constellation shaping improves spectral efficiency, its application to quadrature phase-shift keying (QPSK) remains limited. We address this limitation by incorporating a short shaping code into low-density parity-check (LDPC)-coded QPSK systems. Specifically, a subset of LDPC codeword bits is used as shaping bits and mapped by the shaping code to a sparse codeword that enables probabilistic shaping by controlling non-equiprobable selection between lower- and higherenergy QPSK constellations. Because zeros dominate the sparse codeword, lower-energy constellation points are transmitted more frequently, yielding a Gaussian-like symbol distribution. By exploiting the channel-code protection of the shaping bits, we develop receiver
algorithms that refine shaping-bit log-likelihood ratios (LLRs) using LDPC decoder feedback. Joint optimization of the shaping codebook, bit-to-symbol mapping and constellations enables the proposed shaping scheme to achieve gains of up to 0.6 and 0.53 dB over 5G New
Radio (NR) LDPC-coded QPSK and QAM-16, respectively.
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All authors Heping Wan, Joonyoung Cho, Sandesh Rao Mattu, Jamin Shah, Nishant Mehrotra, Charlie Jianzhong Zhang, Robert Calderbank
Machine Learning
IrekoGPT: Turning Structured Pruning into Post-Hoc Slimmable LLMs
Pietro Moriello, Pietro Buzzega, Angelo Porrello et al. (+1 more)
We introduce IrekoGPT, a post-hoc method for converting pretrained LLMs into slimmable models whose width can be adjusted at inference time. Building on SliceGPT, we retain its projection
matrices without
pruning them, allowing a single model to expose nested subnetworks at different widths. We improve robustness by calibrating each layer across multiple compression ratios, and correct downstream linear layers through gradient-free ridge regression. Across Llama and Qwen models, preliminary results show improvements over naive PCA-based slimming, with the largest gains at high compression. Code is available at https://github.com/aimagelab/IrekoGPT
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All authors Pietro Moriello, Pietro Buzzega, Angelo Porrello, Simone Calderara