The C60 cage is genus zero, its continuum limit is a sphere with twelve conical defects, and its two natural refinements are flow-inequivalent: twelve pentagons forced two ways, a defect charge of one sixth of a full turn per pentagon, and a symbolic

The graph of the fullerene C60 is genus zero, forced two independent ways, and its symmetry-preserving continuum limit is a 2-sphere carrying exactly twelve conical defects, not a torus and not any higher-genus surface. The combinatorial route is Euler's formula: for a trivalent map built only from pentagons and hexagons, edge counting gives f₅ = 6χ, so a sphere forces exactly twelve pentagons, which C60 has, while a torus would force a pentagon-free map. The energetic route is independent. The twelve pentagon centers sit at the vertices of a regular icosahedron, which is also the minimum-energy configuration of twelve mutually repelling charges on a sphere, the Thomson problem at twelve points, with energy 49.165253. In the Goldberg-Coxeter continuum limit the hexagonal regions flatten and the whole curvature concentrates at the twelve pentagon sites, each an angle deficit of π/3, one sixth of a full turn, the twelve summing to 4π as Gauss-Bonnet requires. The defect charge is 1/6 per pentagon in units of a full turn. A model that treats the C60 carrier as a torus is therefore not supported by the geometry. Separately, the two refinements the cage carries, the four-child area refinement of the sphere and a scale ladder that changes length by a fixed factor per level, are flow-inequivalent as shifts of finite type: their signed Bowen-Franks groups are Z/3 and 0, so no flow equivalence identifies one refinement level with a fixed number of ladder steps, and the registration between them is a free normalization. Every number is regenerated by the accompanying script, 14 checks, 14 pass.

Authors

Publication Details

Journal
Zenodo (CERN European Organization for Nuclear Research)
Published
2026-10-29
DOI
https://doi.org/10.5281/zenodo.23774784
Primary Topic
Geometric Analysis and Curvature Flows
Type
preprint
Controls
|||
ALL TIME
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
preprint

The C60 cage is genus zero, its continuum limit is a sphere with twelve conical defects, and its two natural refinements are flow-inequivalent: twelve pentagons forced two ways, a defect charge of one sixth of a full turn per pentagon, and a symbolic

Jason Almasy
1 links
Zenodo (CERN European Organization for Nuclear Research)
Geometric Analysis and Curvature Flows
preprint

The C60 cage is genus zero, its continuum limit is a sphere with twelve conical defects, and its two natural refinements are flow-inequivalent: twelve pentagons forced two ways, a defect charge of one sixth of a full turn per pentagon, and a symbolic

Jason Almasy
preprint en

Abstract

The graph of the fullerene C60 is genus zero, forced two independent ways, and its symmetry-preserving continuum limit is a 2-sphere carrying exactly twelve conical defects, not a torus and not any higher-genus surface. The combinatorial route is Euler's formula: for a trivalent map built only from pentagons and hexagons, edge counting gives f₅ = 6χ, so a sphere forces exactly twelve pentagons, which C60 has, while a torus would force a pentagon-free map. The energetic route is independent. The twelve pentagon centers sit at the vertices of a regular icosahedron, which is also the minimum-energy configuration of twelve mutually repelling charges on a sphere, the Thomson problem at twelve points, with energy 49.165253. In the Goldberg-Coxeter continuum limit the hexagonal regions flatten and the whole curvature concentrates at the twelve pentagon sites, each an angle deficit of π/3, one sixth of a full turn, the twelve summing to 4π as Gauss-Bonnet requires. The defect charge is 1/6 per pentagon in units of a full turn. A model that treats the C60 carrier as a torus is therefore not supported by the geometry. Separately, the two refinements the cage carries, the four-child area refinement of the sphere and a scale ladder that changes length by a fixed factor per level, are flow-inequivalent as shifts of finite type: their signed Bowen-Franks groups are Z/3 and 0, so no flow equivalence identifies one refinement level with a fixed number of ladder steps, and the registration between them is a free normalization. Every number is regenerated by the accompanying script, 14 checks, 14 pass.

Zenodo (CERN European Organization for Nuclear Research)
Geometric Analysis and Curvature Flows
AI Navigator

Ask Laika to Summarize, Analyze, and Connect papers live on the map.

Summarize Papers & Methodologies

Extract key findings, datasets, and comparative methods across publications.

Benchmark Rankings & Visual Analytics

Rank top research institutions, authors, funders, topics, and journals by Field-Weighted Citation Impact (FWCI) and paper volume with instant charts.

Connect Distant Disciplines

Bridge topological clusters on the map to find hidden collaborative intersections.

Laika access coming soon