weekly-papers-2026-06-27

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Bitcoin: A Peer-to-Peer Electronic Cash System

Weekly Paper Notes — Seminal Paper of the Week for the 2026-06-27 CS paper digest. Area: Distributed Computing. Author: Satoshi Nakamoto Published: October 31, 2008 (cryptography mailing list) Canonical URL: bitcoin.org/bitcoin.pdf This week’s digest had a fresh paper on transaction-fair ordering on DAGs without weak edges (Tilikum, 2606.27250) — a piece of work whose entire problem statement (DeFi, BEV, reordering attacks) only exists because of one nine-page document published seventeen-and-a-half years ago to a small cryptography mailing list....

Hallucination in World Models is Predictable and Preventable

Weekly Paper Notes — one of the top picks from the 2026-06-27 CS paper digest. Area: AI / ML. Authors: Nicklas Hansen, Xiaolong Wang (UC San Diego) arXiv: 2606.27326 · PDF · Interactive TL;DR Generative action-conditional world models produce visually fluent rollouts that drift from the true dynamics — the “fluent but wrong” failure mode familiar from LLMs, now in video. Hansen and Wang argue this is fundamentally a data coverage problem: hallucinations concentrate in regions of state-action space the training set under-samples, and cheap data-centric signals computed at inference time can both detect and prevent them....

When Does Combining Language Models Help? A Co-Failure Ceiling on Routing, Voting, and Mixture-of-Agents Across 67 Frontier Models

Weekly Paper Notes — one of the top picks from the 2026-06-27 CS paper digest. Area: AI / ML. Authors: Josef Chen arXiv: 2606.27288 · PDF TL;DR The paper formalizes a hard accuracy ceiling for any multi-model LLM system whose final output is one member’s answer — routing, voting, cascades, fusion, mixture-of-agents. That ceiling is 1 − β, where β is the co-failure rate: the fraction of queries on which every model in the pool is wrong simultaneously....