didericis b27a4d20a3 coloring_nested_tire_graphs: rainbow-conjecture proof sketch + threshold counterexample
Attempts to prove the antipodal-chord rainbow conjecture; result is
nuanced:

1. Upper bound (proven cleanly): pi_D ⊆ {σ : (σ_0..σ_{m/2-1}) and
   (σ_{m/2}..σ_{m-1}) are both perms of {1,2,3}}.  This follows
   from the proper-coloring constraint at the two O-face dual
   vertices, each of degree m/2 in T'_{f'}.

2. Lower bound at m_1 ≥ m - 1 (constructive): every σ in the
   above set extends to a proper edge 3-coloring of T'_{f'}.
   Explicit construction at m=6, m_1=6.  In particular rainbow
   ⊂ pi_D.

3. Counterexample at m_1 ≤ m - 2 (refutes original conjecture):
   at m=6, m_1=4, the rainbow σ = (1,2,3,2,3,1) is NOT in pi_D.
   Explicit forcing-propagation contradiction: two length-1
   inter-D-position gaps on T'_ann force conflicting cycle-edge
   colors at a U-position.  Empirically |pi_D| = 18 (half the
   full set) at m=6, m_1 ∈ {3, 4}.

REVISED conjecture: pi_D equals the full "perm-per-face" set
(containing the rainbow orbit) iff m_1 ≥ m - 1.  The threshold
m_1 ≥ m - 1 is sharp.  Verified for m=4 (all m_1 ≥ 3) and m=6
(m_1 ≥ 5).

Consequence: chain-pigeonhole at γ length m reduces to a smaller
overlap condition under m_1 ≥ m - 1.  The case m_1 < m - 1
remains open -- pi_D still nonempty but the rainbow orbit is
missing; structural characterization of the surviving 18-element
support not addressed.

Note: rainbow_proof_sketch.tex (3 pages).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-26 03:48:48 -04:00
2026-04-12 22:23:55 -04:00
2026-04-20 16:32:27 -04:00
2026-04-20 16:32:27 -04:00
2026-04-20 17:00:04 -04:00
2026-04-20 16:32:27 -04:00
2026-04-17 00:54:42 -04:00
2026-05-09 11:34:58 -04:00

math-research

Personal mathematics research repository by Eric Bauerfeld. Papers are written in AMS-LaTeX using the amsart document class.

Papers

kempe_style_search_for_smaller_contradiction

Humans Suffice: A Novel Proof of the Four Color Theorem

An in-progress proof of the Four Color Theorem via a minimal counterexample argument. The paper builds on Kempe's 1879 strategy — establishing valid cases for vertices of degree ≤ 4, then extending the argument to the degree-5 case using properties of non-adjacent degree-5 vertices, merged subgraphs, and locked colorings.

plane_depth_labelling

Plane Depth Labelling

Early-stage paper. Title and author information set; content in progress.

Creating a New Paper

Use run.sh to scaffold a new paper from the AMS-LaTeX template:

./run.sh init_paper "Your Paper Title"

This creates a new directory (name derived from the title) containing a paper.tex pre-filled with the title and author.

Setup

The Python library code in lib/ requires SageMath. Run setup once per machine:

./run.sh setup <sage_python_path> <sage_site_packages> [system_name]
  • sage_python_path — path to the SageMath Python interpreter (e.g. /opt/sage/local/bin/python3)
  • sage_site_packages — path to SageMath's site-packages directory
  • system_name — optional label for this machine (defaults to hostname -s); used to store per-machine env files as .env.<system_name>

On subsequent runs the paths default to whatever was saved in .env, so ./run.sh setup alone re-runs setup with the existing configuration.

Setup also compiles the plantri submodule via make.

Running Sage

To run a Sage script with plantri available on PATH:

./run.sh sage <script.py> [args...]

Or to open an interactive Sage session:

./run.sh sage

Linting

./run.sh lint

Runs pyright and pylint on lib/ using the SageMath Python interpreter.

Shell Completion

To enable tab-completion for run.sh in zsh, add this to your .zshrc:

eval "$(path/to/run.sh completion)"

Or source it once in the current shell session:

eval "$(./run.sh completion)"

Building

Papers are compiled with LaTeX. From within a paper directory:

latexmk -pdf paper.tex
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