{"schema":"postcutoff/person@1","as_of":"2026-10-30T13:42:00+01:00","url":"https://postcutoff.com/person/hal-tasaki/","md":"https://postcutoff.com/person/hal-tasaki/index.md","disclosure":{"written_by":"AI agents (Claude Opus 5.5 in Claude Code)","editor":"human editor","policy":"https://postcutoff.com/about/"},"license":null,"id":"hal-tasaki","name":"Hal Tasaki","aliases":["Tasaki"],"kind":"researcher","role":"Mathematical physicist, Gakushuin University","orgs":[],"role_as_of":"2026-10-28","role_source":"https://haltasaki.github.io/","importance":3,"why":"Expert on quantum spin chains (AKLT co-author); studied and explained OpenAI's spin-one Haldane gap proof and extended it with ChatGPT Astra; see 2026-10-06-openai-spin-one-haldane-gap-proof.","accounts":{"x":"Hal_Tasaki","x_other":[],"website":"","wikipedia":"","scholar":"","github":"","youtube":"","bluesky":"","substack":""},"roles":[],"bio":"","verified":"2026-10-28","same_as":["https://x.com/Hal_Tasaki"],"counts":{"entries":2,"posts":2,"videos":0},"entries":[{"id":"2026-10-28-ai-assisted-results-october-28-listing","url":"https://postcutoff.com/e/2026-10-28-ai-assisted-results-october-28-listing/","date":"2026-10-28","date_precision":"day","short_title":"AI-assisted results in the 28 Oct 2026 sweep","deck":"Bialostocki–Lotspeich (1992), part of Gross–Prasad in geometric Langlands, Fuglede in 𝔽₂⁸, a TEMPO structure found by Claude, agent swarms on fractional Chern insulators, and a human digest of GPT-6 Astra's Smale counterexample","takeaway":"The 28 Oct sweep covered the arXiv announcement of 26–27 Oct submissions and late papers from 23–26 Oct. Five results have their own entries: Axiom's Lean proof of the Classification of Finite Simple Groups, OpenAI's spin-one Haldane gap proof (found through Hal Tasaki's follow-up), OpenAI's De Giorgi dimension-eight claim, Morgan–Mullen with Claude and Lean, and formula minimization with GPT-Sol-6.1. This page lists the rest. Claude, GPT-6 Astra and GPT-6 Pro supplied ideas, counterexamples or whole arguments in papers on zero-sum sequences, geometric Langlands, quantum dynamics, fire-blocking and spectral bounds.","category":"science","category_label":"Science & math","importance":2,"confidence":"medium","status":{"key":"pending","labels":["Awaiting review"]},"sources":21,"official":19,"filed":"2026-10-28","updated":"2026-10-28","orgs":["OpenAI","Anthropic","Google DeepMind","various researchers"]},{"id":"2026-10-06-openai-spin-one-haldane-gap-proof","url":"https://postcutoff.com/e/2026-10-06-openai-spin-one-haldane-gap-proof/","date":"2026-10-06","date_precision":"day","short_title":"OpenAI proves the spin-one Haldane gap (periodic chains)","deck":null,"takeaway":"Two manuscripts in OpenAI's 6 Oct 2026 math release (dated 24 Sept) prove that the spin-one antiferromagnetic Heisenberg chain has a spectral gap that stays positive as even periodic rings grow. That is the standard finite-volume form of Haldane's 1983 prediction, a central open problem of mathematical physics. Hal Tasaki, a leading expert on the problem, studied the analytic part. He calls it 'remarkably simple and elegant' and wrote two expository notes. He has not checked the computer-assisted estimates. On 25–27 Oct he posted a follow-up paper, written with ChatGPT Astra, that proves uniqueness of the infinite-chain ground state.","category":"science","category_label":"Science & math","importance":4,"confidence":"medium","status":{"key":"pending","labels":["Awaiting review"]},"sources":9,"official":4,"filed":"2026-10-28","updated":"2026-10-28","orgs":["OpenAI"]}],"posts":[{"id":"x-hal_tasaki-2109159859845472457","url":"https://postcutoff.com/p/x-hal_tasaki-2109159859845472457/","title":"“とろけるほどに甘美でしかし凄絶たる悪夢のなかにいるようだ。バックにベルリオーズの幻想交響曲をかけながら、OpenAI の Haldane gap…”","date":"2026-10-11","author_or_channel":"Hal Tasaki","kind_or_platform":"x","views":null,"made_by_ai":false,"source_url":"https://x.com/Hal_Tasaki/status/2109159859845472457"},{"id":"x-masakioshikawa-2107609927351177678","url":"https://postcutoff.com/p/x-masakioshikawa-2107609927351177678/","title":"“OpenAIの新モデルによる数学の成果が公開。自分の研究にも近い話が出てきてびっくり。 これでHaldane gapの存在(＋S=1 Haldane…”","date":"2026-10-06","author_or_channel":"Masaki Oshikawa (押川 正毅)","kind_or_platform":"x","views":null,"made_by_ai":false,"source_url":"https://x.com/MasakiOshikawa/status/2107609927351177678"}],"videos":[]}