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Daily report

AI and science frontiers · 2026-11-01

Only content delivered through the publication boundary on this date is included.

Sealed edition v1

arXiv

The missing factor in counting C4-free graphs is closed: the count on n vertices lands at exponent 3/2

How many graphs on n vertices contain no four-cycle was known only up to a constant factor in the exponent, with a gap between the Kleitman–Winston upper bound and the matching lower bound. The count is now proved to be 2O(n3/2)2^{O(n^{3/2})}, answering a question of Erdős. The proof applies the hypergraph container method only to four-cycles whose two diagonals both have small codegree, defers the rest to counting inside each container, and adds a new bound on the number of matchings in a graph.

arXiv

AI agents vote down their own run: a diamond-spin lab rejects a passing experiment, then earns the evidence

A laboratory of large-language-model agents, each holding a separate research role, asked how many calibration measurements are needed to predict a diamond nitrogen-vacancy spin ensemble's response to arbitrary phase-controlled microwave pulse sequences. The principal-investigator agent tightened a proposed bound of 91 calibrations to an exact minimum of 10; the first acquisition met all ten precommitted accuracy criteria but failed phase and reference controls and was ruled inconclusive, and after the agents revised the protocol without relaxing the criteria, the final measurement supported the prediction while two interpolation methods predicted zero.

arXiv

Electron densities skip the self-consistency loop: one Kohn-Sham step reproduces the self-consistent structure

The electron density is the central variable of density functional theory, and obtaining it normally means iterating to self-consistency. Two Transformer-inspired networks, SwinUNETR-V2 and its attention-free counterpart NeXtUNETR, predict the density directly, reaching normalized mean absolute density errors of 0.075% and 0.046% on QM9. For NeXtUNETR, a single Kohn-Sham step on the predicted density reproduces the self-consistent electronic structure, with median errors of 0.036 meV in total energy, 0.65 meV/angstrom in forces and 1.8 meV in the HOMO-LUMO gap.

arXiv

Retrieval stops chasing one gold chunk: Perplexity's new embedders rank answers and their supporting evidence together

Perplexity released the pplx-embed-v2-context family, which distills graded chunk-level relevance from a query-aware context compression model instead of gold-chunk labels, so training targets no longer depend on how a document is chunked. The 9B model beats the strongest baseline, voyage-context-4, by 14.4 points at Answer@10 on context-bench and leads on Q2D-Chunk and ConTEB; the 0.6B model shares the 9B embedding space, so a small model can query an index built with the large one.

arXiv

Mass parameters move into the geometry: deformed Amplituhedron fixes the double-box span and the two-loop walking dimension

Four-point amplitudes on the Coulomb branch of planar super Yang–Mills had a deformed-Amplituhedron description only for a two-parameter mass configuration. Encoding the external massive kinematics in a six-parameter embedding-space Gram matrix, and using copositivity of its inverse to decide which algebraic intersections enter the real positive region, restricts the two-loop canonical numerator to the span of the two planar double boxes. In a three-parameter subfamily the one- and two-loop integrals are given analytically in multiple polylogarithms, the infrared logarithms still exponentiate at two loops, and the two-loop walking anomalous dimension is fixed.

arXiv

Conditional-memory tables stop spending bits by access frequency: gating each lookup cuts DeepSeek table memory from 23.6 to 3.04 GiB

Large language models store part of their factual knowledge in hash tables keyed by preceding token sequences, and low-bit quantization erases long-tail facts first, while giving more bits to frequently accessed rows does worse than choosing at random. GateRQ stores each row as a ladder of residual codes, computes each lookup's gate from a 1-bit code, and reads deeper levels only for the lookups the gate ranks highest. On DeepSeek-V4.1-Flash it cuts table memory from 23.6 to 3.04 GiB per GPU and raises vLLM throughput over FP8 tables in GPU memory by about 11% and about 31% on the two workloads, losing about 1 PopQA point at 1.50 bits per lookup.

Science Advances

AlphaFold 3 scores T cell receptor specificity from sequence alone, reaching a median AUC of 0.92 on held-out class I antigens

Whether a T cell receptor recognizes a given antigen has usually been settled by binding assays or tetramer staining, one receptor at a time. Researchers instead used AlphaFold 3 to predict the peptide-MHC-receptor triad and scored the predicted alignment error at the receptor-peptide-MHC interface. On held-out sets excluded from training, the antigen-centric area under the ROC curve had a median of 0.92 for class I and 0.81 for class II, 0.24 to 0.33 AUC units above the earlier AF2-multimer model.

arXiv

Corrupted distances, still a near-optimal spanning tree: logarithmic approximation under arbitrary tampering, with no true-distance queries

In a metric whose pairwise distances are each corrupted with fixed probability by an adversary, an algorithm sees only the corrupted values. For increase-only, decrease-only and unrestricted corruption, the work gives polynomial-time or quasi-polynomial-time approximations, reaching a logarithmic factor in the unrestricted case that matches the known information-theoretic lower bound, all without querying true distances.

arXiv

No retraining needed for any-order image generation: one position table and an ordering curriculum unlock inpainting from old weights

A pretrained raster-scan autoregressive image model can only generate left to right and top to bottom, so it cannot inpaint or outpaint at inference. A new adaptation adds a future-aware positional embedding table and continues training under a curriculum that shifts from raster order to random order, letting the same weights condition on any ordering. On ImageNet, LlamaGen-XL moves from FID 2.63 to 3.91 but gains inpainting and outpainting while keeping KV caching and vLLM serving.

arXiv

A glance is enough to queue the next actions: symbolic graphs carry kitchen priors, and a 3M-parameter model leads in short-observation tests

SymAnt merges a scene graph and a knowledge graph into one joint graph and uses the symbolic context found by graph search as the starting point for iterative decoding, so it can predict long action sequences from very short observation windows. In the short-observation settings of Breakfast and 50 Salads, its mean accuracy over classes exceeds the neuro-symbolic baseline NeSCA and several large-model baselines; on EPIC-KITCHENS, the 3M-parameter model performs comparably to fine-tuned models with billions of parameters. Because predictions are anchored in an editable graph, users can add or remove nodes at inference time to change predictions without retraining.

arXiv

Multi-token prediction carries a noisy gradient term: stripping it lifts a 1.2B model past next-token prediction on zero-shot accuracy

Multi-token prediction (MTP), which trains a language model to predict several future tokens, is now a common pre-training ingredient, but its standard cross-entropy gradient contains a low signal-to-noise residual that grows noisier with scale. Soft-MTP removes that residual and backpropagates only the KL self-distillation signal hidden inside it, reusing cross-entropy gradients already computed and materializing no vocabulary-sized logit matrices, as a one-line code change. On LLaMA-style models from 167M to 1.2B parameters, Soft-MTP beats standard MTP at every scale with lower next-token perplexity, faster self-speculative decoding and higher zero-shot accuracy; from 689M it also lowers MTP perplexity, and at 1.2B it gives stronger math and code reasoning after fine-tuning.

Ai2 Blog

A novelty judge can look reliable until the prompt changes: GPT-5.4 falls from 93.5% to 40.9% on the same idea pairs

Ai2 released Old Ideas, Novel Problems, a study, benchmark and data pipeline testing whether large language models can judge the novelty of research ideas. Across six judges, changing one setting such as the prompt shifted verdicts sharply: GPT-5.4 fell from 93.5% to 40.9% accuracy on human-versus-generated idea pairs, below chance, and purpose-built novelty evaluators were neither more accurate nor cheaper than a simple prompted Claude Opus 4.6 baseline.

arXiv

Neurons have no positions, yet they can be coarse-grained: a renormalization-group map predicts five grokking exponents within 1%–10% of direct fits

Deep networks on modular addition memorize the training set and generalize only long afterward, a delay called grokking. Treating training epoch as temperature and weight decay as a conjugate field, the study builds neuron-to-neuron couplings from second derivatives of the loss in per-neuron norm coordinates, orders neurons along the Fiedler vector of that coupling graph, and runs a real-space renormalization group on the resulting one-dimensional chain. Five critical exponents from the blocking map agree with values fitted directly from 30 independent training runs to within 1%–10%.

bioRxiv

Spatial transcriptomics skips the region map: 45.8% more DE genes in chronic stress, with attention maps showing where

Comparative spatial transcriptomics usually partitions tissue into anatomical regions or clusters first and then tests differential expression inside those fixed units, separating localization from testing. SpaceDX instead learns gene-specific spatial attention weights while testing, aggregating spots into an attention-weighted pseudobulk that enters a hierarchical Bayesian logistic regression for subject-level association. In 19 stressed and 19 control mice it found 175 DE genes at 5% empirical FDR, 45.8% more than regional DESeq2's 120; in an Alzheimer's model the two found similar numbers alone, and combining them raised discovery 19.1% over DESeq2 alone.

arXiv

No tactile glove required: monocular video yields contact, proximity and 3D force, lifting HOCap contact Macro-F1 from 18.0 to 50.5

TactoHand unifies contact, proximity and 3D vertex force into dense fields on the hand surface inferred from monocular video, removing the need for the specialized hardware that tactile collection requires. A temporal transformer aggregates visual evidence across frames, and a differentiable rigid-body layer ties predicted forces to observed object motion. On HOCap, excluded from training, contact Macro-F1 reaches 50.5 against 18.0 for HACO, and physics supervision lowers the temporal variant's rollout position error from 5.7 cm to 3.3 cm.

arXiv

How many rules can a model hold at once? GPT-4o mini keeps about 37–38 at 95% correct

Instruction-following quality falls as load grows, but there was no load-denominated capacity with an uncertainty. A measurement instrument defines load as single-word replacement rules, making each application a program-checkable Bernoulli trial, then inverts a binned-then-smoothed statistical model to obtain capacity. For GPT-4o mini, 2958 requests and 642430 trials give a capacity of about 37–38 rules at a 0.95 share of right replacements and about 18–19 rules at full replacement density.

arXiv

An open post-training recipe makes fact-checking models harsher on low-status posters, while seven deployed models show no such tilt

On fact-checking claims with randomized poster profiles, the open Tülu-3 post-training recipe makes OLMo-2 32B and Tülu-3 70B judge claims from lower-status posters false more often, an effect under one percentage point but statistically reliable, exceeding training drift and replicating on independent claim sets; Meta's, Alibaba's and Mistral's recipes do not produce it. In OLMo-2 32B the model does not notice the job more but interprets it differently, with a lower-status job pushing the base model toward true and the post-trained model toward false, a flip carried by a single residual-stream direction at supervised fine-tuning. None of seven deployed commercial models doubts lower-status posters more.

bioRxiv

One stretch of DNA, four evolutionary forces: multiscale haplotype images lift classification accuracy to 90.85%

Telling neutrality, selective sweeps, balancing selection and adaptive introgression apart is hard because the haplotype footprints these processes leave overlap. SHADES renders haplotype frequencies, differences between frequency distributions, and sequence differences between ranked haplotypes as three image types, trains convolutional networks at window sizes of 11, 21 and 51 SNPs, and stacks the three scales for four-class classification. On simulated test replicates, the deeper SHADES[M2] reached 90.85% overall accuracy, against 67.83% for SURFDAWave, 68.30% for diploS/HIC, 65.20% for TrIdent, 63.20% for FAST-NN and 79.43% for FASTER-NN on the same test set.

arXiv

Few-step text-to-image gains a feature-moment constraint: Z-Image-Turbo hits 94.25% on Chinese LongText-Bench at two evaluations

Few-step text-to-image generation must render prompt details with very few sampling steps, and distribution matching distillation (DMD) relies on learned score differences whose statistics need not align. Intrinsic Distribution Matching keeps the full DMD correction and adds a moment constraint on the means and per-coordinate standard deviations of the generator's exponential-moving-average features, with no external feature encoder. On Z-Image-Turbo 6B at two network evaluations it reaches 94.25% and 90.20% on Chinese and English LongText-Bench, the highest scores among the compared methods at that budget.

arXiv

More Communication Can Widen the Generalization Gap in Streaming Federated Learning, Bounds Grow With √R

Streaming federated learning trains a shared model from continuously arriving client data, whose streams are often temporally dependent. For clients whose data follow Markov processes, an analysis uses information-theoretic and rate-distortion tools to bound the expected generalization gap of the aggregated model, specializing to linear and self-attention next-token prediction. The bounds show that more communication rounds loosen the guarantee at roughly √(R/N), while temporal dependence enters through the square root of the mixing time; GPT-style pretraining on TinyStories and ETTh2 forecasting both show train and test losses falling with rounds while the gap widens.

Harmonic

Aristotle Brings Formal Verification to C and Verilog, Finding Bugs 110,000 Cycles Deep in Tensordyne's Hardest Block

Harmonic has extended Aristotle, previously applied to research mathematics, to formal verification of software and hardware, starting with C and Verilog. Unlike code review and testing, which examine only a portion of possible behaviors, it uses machine-checked proofs to determine whether specified properties hold across all possible inputs within a defined system, proposing properties from code and reporting which were proved and what assumptions each proof rests on. In the block Tensordyne's team considered hardest to verify, it found bugs up to 110,000 cycles deep; on LibTomMath it fixed three bugs and made modular exponentiation 31–38% faster in Harmonic's benchmarks, with the faster code proved against the same spec.

Luminary Cloud

Aeroelastic coupling stops rerunning CFD every iteration: full-field physics models converge a transonic swept wing in 8 to 11 minutes on one GPU

Static aeroelastic coupling of a transonic swept wing used to rerun CFD at every iteration, taking about four hours to converge. Replacing the flow solve with a full-field physics model that predicts surface pressure and wall shear stress directly from CAD geometry brings the same loop to 8 to 11 minutes on a single T4 GPU; on three wings both loops converged in four iterations and their predicted washout lift loss differed by 0.2 to 0.8 percentage points.

Intrusion alerts stop trusting one model: notary agents and on-chain votes certify a 99.65%-accurate subset

Intrusion alerts no longer trigger remediation on a single model's word: independent notary agents re-check each verdict and co-sign it on a Hyperledger Fabric ledger only after a 2-of-3 quorum. On the class-balanced CICIDS2017 test set the calibrated ensemble reaches 96.60% accuracy over all decisions, and the certified subset reaches 99.65% accuracy at a 0.04% false-positive rate with 87.3% coverage; on the independently generated GeNIS 2025 corpus the same stack certifies 99.86% of flows at 99.98% accuracy.

A browser rewritten for AI agents: not a Chromium fork, claimed 16x lighter and 9x faster across 933 real pages

Lightpanda released a headless browser written from scratch in Zig for AI agents and automation, not a Chromium fork or a WebKit patch. In a benchmark requesting 933 real web pages over the network on an AWS EC2 m5.large instance, it claims to be 16x lighter and 9x faster than Chromium. It exposes a CDP server that existing Puppeteer and Playwright clients connect to, and runs in fetch and serve modes.

Saliency maps for medical image classifiers stop guessing from gradients: unsupervised training lets a frozen classifier check the mask

Saliency maps for convolutional classifiers on medical images now have a new training route: SalientNet needs no annotated saliency ground truth and instead requires the generated mask to keep enough information for a frozen classifier to reproduce its original prediction within a controlled tolerance. Across BreakHis, Brain MRI ND5 and FracAtlas, it reaches higher faithfulness (Win %) and lower prediction Drop (%) than Grad-CAM, Grad-CAM++ and LIME in nearly all dataset-architecture combinations, and on FracAtlas its maps correlate spatially with practitioner-annotated fracture regions, with a mean ground-truth active fraction of up to 0.96 for ResNet-18.

Legal teams get ready-to-use, shareable tools: contracts, regulations and requests each get a place, with a source link on every output

Anthropic released ready-to-use, adaptable and shareable artifacts for legal teams, interactive tools such as trackers and dashboards, and opened a legal gallery covering contract review, regulatory change tracking and intake of legal requests from the business. Legal teams had most often asked for simpler setup and easier collaboration with colleagues; each artifact opens with an example so users see how the work comes together before adding their own data and connectors, and every answer or output links to its source.

Cyber defense simulators stop hard-coding the network: swap the modeling language, train attackers and defenders in one environment

The KTH team released the MAL Simulator, which builds cyber attack and defense simulation on the Meta Attack Language so a new target domain can be modeled without changing simulator source code. Across 30 scenarios derived from the ADS-24 network in the CRATE cyber range, a trained reinforcement-learning attacker returned −301±10.3 on 15 unseen test scenarios, better than breadth-first, depth-first and random search, and a defender trained under 1% false and missed alerts returned −60355±945 against −61653±914 for a heuristic defender. Against the reinforcement-learning attacker, every defender's return dropped markedly.

arXiv

Multifidelity optimization stops letting cheap runs eat the budget: on DTMB 5415 the hull resistance falls further than the single-fidelity baseline

Multifidelity active learning now folds the choice of fidelity into the choice of where to sample, instead of fixing the location first. MF-CAS scores each candidate by the high-fidelity improvement opportunity per unit cost using decomposed uncertainty intervals; on the constrained 14-dimensional DTMB 5415 hull hydrodynamic optimization with a 100 equivalent-high-fidelity budget, its resistance reduction exceeds that of the single-fidelity LCB baseline, while the multifidelity LCB baseline barely improves on the initial design.

Claude adds a usage and cost API that splits bills by model, workspace and API key

Anthropic released a beta Usage and Cost Analytics API on the Claude Platform, with two organization-level endpoints that report token usage and cost for Claude Console and Claude Enterprise organizations and let callers filter and group results by dimensions such as model, workspace, API key, and the user or service account behind each request. The same data previously came from the Usage and Cost API and four report endpoints of the Claude Enterprise Analytics API, which are now legacy but remain supported, with two documented migration paths. The new endpoints require the analytics-usage-cost-2026-08-24 beta header.

arXiv

Differentiable decision trees stop spreading across dozens of features: a Euclidean penalty cuts Wine's effective node features from 8.94 to 1.54

Differentiable decision trees keep explicit paths and end-to-end training, but an oblique soft split at each internal node can depend on many input features at once, weakening node-level readability. EU-DDT adds a normalised squared Euclidean regulariser to the training objective that constrains how far each node's relative feature weights depart from uniform, without changing the sigmoid soft routing. Over five matched random seeds, mean effective features fall from 8.94 to 1.54 on Wine and from 45.28 to 9.06 on Digits, while mean test accuracy moves from 100.0% to 93.9% and from 92.3% to 94.6%, a dataset-dependent trade-off between concentration and performance.

THU-MAIC/OpenMAIC

OpenMAIC 1.3.0 keeps every upload in its owner's knowledge base, parsed once for every classroom conversation

OpenMAIC is an open-source multi-agent platform that turns any topic or document into an interactive classroom, with AI teachers and AI classmates who speak, draw on a whiteboard and discuss in real time. Version 1.3.0 keeps each upload in its owner's knowledge base, organized in folders and parsed once for every conversation, where the agent can read, search and organize it and the composer offers it through @. The Pro workbench also previews the agent's work before the first page exists, and classroom tabs switch between Learn and Edit.

T3 Code puts your local coding agents behind one console, reachable from phone, web and desktop

T3 Code released an agent harness control surface that drives coding agents already installed on a user's machine from one iOS, Android, web and Electron desktop interface. It does not train a model or replace those agents: users must first install and authenticate at least one supported provider, such as Codex, Claude, Cursor, Grok Build, OpenCode, Antigravity or fx, and T3 Code then controls it. The project describes itself as very early, warns of bugs, and is mostly not accepting contributions.