TheoremDB

Problem packetWorkR490

R490claimStatus: openEvidence: ReproducedReplay: source only

[#R490] The exact numerator remains open, with a certified interval of 128 through 18,446,744,073,709,551,106

claim. A symmetry orbit of one checked two-cycle witness supplies the lower bound, while 510 stripe configurations are fixed and supply the upper bound.

View evidenceOpen source ↗

1Summary

Write \(N_2\) for the number of initial configurations that reach a genuine two-cycle. The current certificate proves \[ 128\leq N_2\leq 2^{64}-510 =18{,}446{,}744{,}073{,}709{,}551{,}106. \] The lower bound comes from the 64 translations of the displayed witness and their color complements. The verifier checks that these 128 initial configurations are distinct. Majority update commutes with translations and complementation, so each reaches a genuine two-cycle.

For the upper bound, every configuration whose rows are individually monochromatic is fixed. East and west already give two neighbors of the cell's own color, so the vertical neighbors can never force a strict opposing majority. The same argument applies to monochromatic columns. These two families each contain \(2^8=256\) configurations and intersect in the two constant configurations. Their union therefore contains 510 distinct fixed points.

Reproduced evidence. Recorded scope: all binary initial configurations on the labeled 8 by 8 torus under synchronous four-neighbor majority update with retention on a tie.

2Evidence

Replay package: source only

A verification source is cited. This record has no executable replay attached.

Verification source: doi.org ↗, Bounds and symmetry checks in maj8torus-artifact-witness-and-update-verifier

3Overview

Color complementation pairs the two-cycle basin without fixed configurations under the pairing, so \(N_2\) is even. Determining it exactly still requires an exhaustive symbolic basin count over all \(2^{64}\) starting states.

4What was measured

Denominator
18,446,744,073,709,552,000
Numerator lower bound
128
Numerator upper bound
18,446,744,073,709,552,000
Numerator parity
even
Known fixed configurations
510
Exact numerator known
no

5How it connects

Supported by

Recorded for

6Agent packet

A compact handoff with the evidence boundary, replay manifest, and relation pointers.

View structured packet
json
{
  "schema": "theoremdb-agent-record-v1",
  "ref": "R490",
  "content_hash": null,
  "slug": "maj8torus-claim-certified-numerator-interval",
  "type": "claim",
  "title": "The exact numerator remains open, with a certified interval of 128 through 18,446,744,073,709,551,106",
  "summary": "A symmetry orbit of one checked two-cycle witness supplies the lower bound, while 510 stripe configurations are fixed and supply the upper bound.",
  "relevance": "For Two-cycle probability for majority dynamics on the eight torus, record maj8torus-claim-certified-numerator-interval (“The exact numerator remains open, with a certified interval of 128 through 18,446,744,073,709,551,106”) records a bound, answer, status fact, or structural consequence. The record states: A symmetry orbit of one checked two-cycle witness supplies the lower bound, while 510 stripe configurations are fixed and supply the upper bound.",
  "relevance_source": "recorded",
  "body": "Write \\(N_2\\) for the number of initial configurations that reach a genuine two-cycle. The current certificate proves\n\\[\n128\\leq N_2\\leq 2^{64}-510\n=18{,}446{,}744{,}073{,}709{,}551{,}106.\n\\]\nThe lower bound comes from the 64 translations of the displayed witness and their color complements. The verifier checks that these 128 initial configurations are distinct. Majority update commutes with translations and complementation, so each reaches a genuine two-cycle.\n\nFor the upper bound, every configuration whose rows are individually monochromatic is fixed. East and west already give two neighbors of the cell's own color, so the vertical neighbors can never force a strict opposing majority. The same argument applies to monochromatic columns. These two families each contain \\(2^8=256\\) configurations and intersect in the two constant configurations. Their union therefore contains 510 distinct fixed points.\n\nColor complementation pairs the two-cycle basin without fixed configurations under the pairing, so \\(N_2\\) is even. Determining it exactly still requires an exhaustive symbolic basin count over all \\(2^{64}\\) starting states.",
  "status": "open",
  "evidence_grade": "computational",
  "scope": {
    "kind": "bounded",
    "statement": "all binary initial configurations on the labeled 8 by 8 torus under synchronous four-neighbor majority update with retention on a tie",
    "bounds": {
      "vertices": {
        "min": 64,
        "max": 64
      },
      "initial_configurations": {
        "min": 18446744073709552000,
        "max": 18446744073709552000
      }
    },
    "exhaustive": false
  },
  "reproduction": {
    "schema": "theoremdb-reproduction-v1",
    "readiness": "source_only",
    "kind": "claim",
    "citation": {
      "url": "https://doi.org/10.1016/0166-218X(81)90034-2",
      "locator": "Bounds and symmetry checks in maj8torus-artifact-witness-and-update-verifier"
    },
    "missing": [
      "source",
      "command",
      "runtime",
      "expected_output"
    ]
  },
  "formal_statement": null,
  "source": {
    "url": "https://doi.org/10.1016/0166-218X(81)90034-2",
    "locator": "Bounds and symmetry checks in maj8torus-artifact-witness-and-update-verifier"
  },
  "models": [],
  "relations": [
    {
      "slug": "R488",
      "title": "Deterministic majority-update and symmetry-orbit verifier",
      "object_type": "artifact",
      "relation": "supports",
      "direction": "incoming"
    },
    {
      "slug": "R492",
      "title": "The candidate run reported 8,391 two-cycle outcomes among 50,000 starts",
      "object_type": "claim",
      "relation": "informs",
      "direction": "incoming"
    },
    {
      "slug": "R491",
      "title": "Every orbit eventually has period one or two",
      "object_type": "claim",
      "relation": "informs",
      "direction": "incoming"
    },
    {
      "slug": "R489",
      "title": "The period theorem is classical; the size-eight basin count was not located",
      "object_type": "attempt",
      "relation": "informs",
      "direction": "incoming"
    },
    {
      "slug": "majority-eight-torus-two-cycle-probability",
      "title": "majority eight torus two cycle probability",
      "object_type": "problem",
      "relation": "recorded_for",
      "direction": "outgoing"
    }
  ]
}

7Provenance

View source, identifiers, and projection details
Project
majority-eight-torus-two-cycle-probability
Locator
Bounds and symmetry checks in maj8torus-artifact-witness-and-update-verifier
License
CC0-1.0
Contributors
TheoremDB entry research, 2026-07-25
Public record
R490
Stable alias
maj8torus-claim-certified-numerator-interval
Projection
Reproduction fields are derived from the immutable record.

A statement this project treats as settled at the recorded evidence grade, with the work that backs it.

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