didericis a22ca4b888 Add medial tire cut experiment and chaining section
New experiments/run_medial_tire_cut_experiment.py: generates a random
maximal planar graph (stacked seed + random diagonal flips), builds the
medial graph, takes the tire decomposition at a random vertex level
source, walk-depth labels and cuts each full medial tire graph chained
down the tire tree, and assembles one final cut graph of M(G) with a
global label map (data only; graphics go in a separate script).

Fix label_and_cut: the root face is None, which collided with the
next(..., None) sentinel, leaving teeth unlabelled when the entry up
tooth lay inside a bite gap; use a distinct sentinel so the ascent to
the root face runs.

Add a "Chaining across the tire tree" section to the paper, clarifying
that the candidate parent down teeth are the boundary (singleton) down
teeth only -- bite teeth are interior to the parent and shared with no
child, so a lower-walk bite is skipped.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-06-14 23:46:49 -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
2026-06-08 15:34:53 -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 and live under papers/.

Papers

All papers are at papers/<name>/paper.tex. The current set:

Directory Title
colored_edge_flip_classes Colored Edge Flip Classes
colored_pentagon_contractions Colored Pentagon Reductions
coloring_nested_tire_dual_graphs Coloring Nested Tire Dual Graphs
even_level_graph_generators Even Level Graph Generators: a constructive conjecture stronger than the Four Color Theorem
face_monochromatic_pairs Face-Monochromatic Pairs and the Four Colour Theorem
iterated_reduction_in_reduced_dual An Iterated Reduction in the Reduced Dual
level_resolutions_of_maximal_planar_graphs Level Resolutions of Maximal Planar Graphs
level_switching Level Switching
medial_tire_decompositions_of_plane_triangulations Medial Tire Decompositions of Plane Triangulations
nested_tire_decompositions_of_plane_triangulations Nested Tire Decompositions of Plane Triangulations
plane_depth Plane Depth
plane_depth_sequencing Plane Depth Sequencing
plane_diamond_coloring Plane Diamond Coloring

The papers form a connected programme around plane triangulations, BFS-level structure, and the Four Colour Theorem. plane_depth introduces the level / dual-depth framework that downstream papers build on; nested_tire_decompositions_of_plane_triangulations develops the tire-tread tree-of-treads decomposition.

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 papers/<name>/ (the name is derived from the title, lower-cased, spaces → underscores) 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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