User:Tomruen/Coxeter foldings

Coxeter group	Coxeter diagram	Degrees	Coxeter planes
A2		2, 3	A1, A2
B2		2, 4	A1, B2
H2		2, 5	A1, H2
A3		2, 3, 4	A1, A2, A3
B3		2, 4, 6	A1, B2, A2=B3
H3		2, 6, 10	A1, A2, H2=H3
A4		2, 3, 4, 5	A1, A2, A3, A4
B4		2, 4, 6, 8	A1, A3, B2, A2=B3, B4
D4		2, 4, 6	A1, A3, A2=D4
F4		2, 6, 8, 12	A1, A3=B2, A2=B3, F4
H4		2, 12, 20, 30	A1, A2, A3, H2=H3, H4
A5		2, 3, 4, 5, 6	A1, A2, A3, A4, A5
B5		2, 4, 6, 8, 10	A1, A3=B2, A2=B3, B4, A4=B5
D5		5; 2, 4, 6, 8
A6		2, 3, 4, 5, 6, 7	A1, A2, A3, A4, A5, A6
B6		2, 4, 6, 8, 10, 12	A1, A3=B2, A2=B3, B4, A4=B5, B6
D6		2, 4, 6, 8, 10
E6		2, 5, 6, 8, 9, 12
E7		2, 6, 8, 10, 12, 14, 18
E8		2, 8, 12, 14, 18, 20, 24, 30

Finite Coxeter group foldings

I'm curious to Coxeter–Dynkin_diagram#Geometric_foldings expressing Coxeter numbers and all degrees of fundamental invariants. Foldings are shown by marking node with colors, red and blue, which map to node 1 or 2 in the rank 2 folded group.

A3

Example: A₃,

Folding		Degree	Coxeter Plane
		4	A3
		3	A2
		2	A1

B3

Example: B₃,

Folding		Degree	Coxeter Plane
		6	B3
		4	B2
		3	A2
		2	A1

H3

Example: H₃,

Folding		Degree	Coxeter Plane
		10	H3
		5×2	H2
		3×2	A2
		2	A1

A4

Example: A₄,

Folding			Degree	Coxeter Plane
			5	A4
			4	A3
			3	A2
			2	A1

B4

Example: B₄,

Folding			Degree	Coxeter Plane
			8	B4
			6	B3
			4	A3
			4	B2
			3	A2
			2	A1

F4

Example: F₄,

Folding			Degree	Coxeter Plane
			12	F4
			6	B3
			4	A3
			4	B2
			3	A2
			2	A1

H4

Example: H₄,

Folding			Degree	Coxeter Plane
			30	H4
			10	H3
			5	H2
			4	A3
			3	A2
			2	A1

A5

Example: A₅,

Folding			Degree	Coxeter Plane
			6	A5
			5	A4
			4	A3
			3	A2
			2	A1