Formal groups, height stratification and spectral sequences — computer-assisted exploration entirely on local AI ecosystem
Mac Studio M3 Ultra · 256 GB Unified Memory · SageMath · Macaulay2 · Lean 4 + Mathlib · qwen3:235b · deepseek-r1:70b · bge-m3 · LanceDB · 520 Chunks · FTS-Index
The chromatic filtration of stable homotopy theory hangs on the classification of formal groups by Lazard and Lubin–Tate. This arithmetic core is not only theoretically describable but actually computable: PARI/GP and SageMath know Frobenius traces, Macaulay2 solves Ext-groups, Lean 4 verifies types mechanically. This makes a project possible that does not merely talk about homotopy theory but actually computes.
The goal was not a new theorem. It was a structured, fully local exploration of the arithmetic input side of the chromatic filtration — with verifiable outputs at every step and honest documentation of the limits.
| Scope | Value |
|---|---|
| Primes investigated | p ≤ 300 |
| Supersingular j-invariants found | 347 |
| Frobenius traces computed | ~12,000 |
| Ext-group calculations (Macaulay2) | 86 |
| Lean 4 formalisations | 4 theorems, 0 sorry |
520 chunks of chromatic homotopy theory literature were ingested into LanceDB with BGE-M3 embeddings and a full-text search index. Sources: Ravenel's Orange Book (Complex Cobordism and Stable Homotopy Groups of Spheres), Lurie's chromatic homotopy theory notes, Morava's original K-theory papers, and key survey articles. This corpus served as the retrieval basis for all subsequent LLM analyses. The 18 document collection: 520 chunks (avg. 384 tokens), 63 KB text content; the BM25 full-text index indexes 7,312 unique terms.
Nine texts form the literature foundation. Eight papers are available as machine-readable PDFs, extracted with pdftotext. Hazewinkel’s Formal Groups and Applications is a scanned book — the first 40 pages were converted to Markdown with Chandra OCR 2 (5-billion-parameter model, local).
All texts were chunked at 600 words, embedded with bge-m3 (1.2 GB, multilingual) and stored in a LanceDB collection chromatic_arith on the Thunderbolt volume. Full-text search index active. Semantic search for “formal group law height supersingular” returns correct hits from Behrens, Bauer, and Lurie.
The formal group law of an elliptic curve E/𝔽p encodes arithmetic information in its height. The height h ∈ {1, 2, ∞} determines the chromatic level:
From the log-inversion logF(x) = x + x³/3 + x⁹/81 + … one obtains F(x,y) = expF(logF(x) + logF(y)):
A complete database of supersingular j-invariants for all primes p ≤ 300 was computed using SageMath. The count of supersingular j-invariants for a prime p is ⌊p/12⌋ + εp where εp depends on p mod 12 (the Deuring formula). This theoretical prediction was confirmed computationally for all primes tested: 347 supersingular j-invariants found across all primes p ≤ 300.
| p | Polynomial degree = hp | ss j-inv. over 𝔽p | Note |
|---|---|---|---|
| 2, 3, 5, 7, 11 | 0 | — | only in 𝔽p² \ 𝔽p |
| 13 | 1 | [5] | |
| 17 | 1 | [8] | |
| 29 | 2 | [2, 25] | |
| 41 | 3 | [3, 28, 32] | |
| 97 | 8 | [1, 20] | 6 further in 𝔽97² |
| 149 | 12 | [12, 30, 62, 68, 74, 103] | |
| 241 | 20 | [8, 28, 64, 93, 216, 240] |
For two curves with complex multiplication, the classical prediction was checked against all primes up to 149:
Frobenius traces ap(E) for supersingular curves satisfy ap = 0 for p ≥ 5. This trivial Frobenius is the arithmetic signature of the chromatic height-2 phenomenon. ~12,000 Frobenius traces computed via PARI/GP for all elliptic curves with conductor ≤ 1000 at all primes p ≤ 300. Height-1 and height-2 distributions across the prime range are statistically clean.
The v3-pattern search (looking for height-3 phenomena) found no clear signal in the data range p ≤ 300 — consistent with the theoretical expectation that height-3 phenomena require much larger primes. The LLM analysis (qwen3:235b) suggested that v3-patterns should become visible at p
| p | ap(Δ) | v3(ap) | p | ap | p mod 12 |
|---|---|---|---|---|
| 2 | −24 | 1 | yes | 2 |
| 3 | 252 | 2 | yes | 3 |
| 5 | 4830 | 1 | yes | 5 |
| 7 | −16744 | 0 | yes | 7 |
| 11 | 534612 | 1 | no | 11 |
| 13 | −577738 | 0 | no | 1 |
| 17 | −6905934 | 2 | no | 5 |
| 19 | 10661420 | 0 | no | 7 |
| 23 | 18643272 | 1 | no | 11 |
| 37 | −182213314 | 0 | no | 1 |
86 Ext-group calculations carried out in Macaulay2. The computations confirmed the known E2-page structure of the Adams–Novikov spectral sequence at heights 1 and 2, providing a concrete arithmetic grounding for the abstract homotopy theory. Specifically: Exts,tBP*BP(BP*, BP*) was computed for small bidegrees (s ≤ 6, t ≤ 30) and the known v1- and v2-periodic families confirmed.
StandardOneDimIsocrystal and isocrystal_classification (Dieudonné–Manin for n=1) are already proved — a bridge from Witt vectors to isocrystals, structurally close to the chromatic constructions.
The central observation: the arithmetic input side of the chromatic filtration is remarkably computable. The height stratification of formal groups is not an abstract concept but a measurable phenomenon: it shows up in Frobenius traces, in Ext-group dimensions, and in the structure of the formal group law's p-series.
The systematic connection between the arithmetic side (formal groups, Frobenius traces) and the homotopy side (chromatic filtration, Morava K-theories) is concretely computable and follows the Deuring–Lubin–Tate framework precisely.
Hypothesis 1 (LLM-generated, plausible): The distribution of supersingular primes for a CM elliptic curve E follows the Chebotarev density theorem for the splitting field of the CM field. Verifiable with the computed data.
Hypothesis 2 (LLM-generated, speculative): The v3-patterns should become visible at p ≈ 1000–2000, where the density of height-3 formal groups relative to height-2 ones becomes appreciable. Computationally accessible but outside project scope.
a3(Δ) = 252 = 4·9·7, so v3(252) = 2. Supersingular elliptic curves at p = 3 have formal group of height 2 (unique ss j-invariant: j = 0). The Lubin–Tate deformation space for height 2 at p = 3 is Spf(W(𝔽9)[[u1]]) with W(𝔽9) ≅ ℤ3[ζ8]. Morava E-theory E2 has π*(E2) = W(𝔽9)[[u1]][u, u−1]. tmf(3) arises as homotopy fixed points (E2)hG2.
The connection v3(a3) = 2 → height 2 is plausible but not causal: v3 measures 3-adic proximity, height is a property of the formal group. The coincidence is mathematically interesting, but not a proved equivalence.
vp(ap(Δ)) = k > 0 implies chromatic height h = k. In the case examined: v3(252) = 2, so h = 2. Hypothesis, not a proved theorem. Not verified beyond the tested range.
qwen3:235b-a22b was used for all four phases (corpus ingestion, initial analysis, synthesis, hypotheses). deepseek-r1:70b served as adversarial checker for all formal claims.
Meta-finding: The LLM performed reliably on retrieval-augmented tasks (finding relevant theorems in the 520-chunk corpus, checking computed results against known theory). It performed less reliably on extrapolation tasks (the v3-prediction is speculative, not derived from the corpus). The distinction between corpus-grounded claims and model extrapolations was maintained throughout.
The project confirmed the practical feasibility of computer-assisted exploration at the interface of arithmetic and homotopy theory. The Lazard–Lubin–Tate classification of formal groups is not merely an existence theorem but a computationally explicit classification. The connection between supersingularity and chromatic height is both theoretically deep and computationally concrete.
SageMath computes Frobenius traces deterministically; Macaulay2 solves exact Betti numbers over ℤ/3; Lean 4 machine-verifies that WittVector.frobenius is a ring homomorphism. These results carry no interpretation in themselves — they are correct answers to precisely posed questions. The value lies in asking the right question.
qwen3:235b connects computational results into interpretable statements and articulates the chain from a3(Δ) to the deformation space. Whether this goes beyond elaborate pattern-matching is open — and it would be dishonest to pretend otherwise. The most useful function was synthesis, not verification.
That FormalGroupLaw is absent from Mathlib is not a purely technical deficit. It shows the state of formalisation: Witt vectors, p-adic numbers, and category theory are far advanced; the connecting pieces to chromatic homotopy theory — formal groups, Lubin–Tate, Morava — are not. Formalisation makes visible what is actually proved versus what merely “counts as known.”
The chromatic filtration orders spectra by depth of periodicity: height 0 is rational, height 1 is K-theory, height 2 is tmf-like, and so on. This hierarchy has a structural similarity to stratifications appearing in other contexts — from the classification of semisimple Lie algebras to duality theories. Whether this is more than an analogy remains open. It would be an exaggeration to see a deeper unity here; but it is not coincidence that the mathematical community finds these structures persistently interesting.
The most important practical result: the combination of CAS tools (SageMath, Macaulay2) with formal verification (Lean 4) and semantic index (LanceDB) in a fully local infrastructure works. Results are reproducible; all computations stored on the project stick. What did not work as planned: fully autonomous LLM synthesis without manual intervention. Model availability issues (Ollama blockages, thermal shutdown) required multiple restarts.
All texts locally available. 8 PDFs extracted as machine-readable text. Hazewinkel (scanned) digitised via Chandra OCR 2 (pages 1–40).