# 龐加萊(Poincaré)十二面體空間 # # 二次二十面體群作用於3維球面所得到的商空間就是著名龐加萊十二面體空間。 # 群的矩陣元素屬於域Q[φ],其中 φ = (1 + √5)/2 ≈ 1.6180339887... # 是黃金分割率並且是不可約多項式 φ² - φ - 1 的根。 0.80901699437494742410 -0.50000000000000000000 0.00000000000000000000 -0.30901699437494742410 0.50000000000000000000 0.80901699437494742410 0.30901699437494742410 0.00000000000000000000 0.00000000000000000000 -0.30901699437494742410 0.80901699437494742410 0.50000000000000000000 0.30901699437494742410 0.00000000000000000000 -0.50000000000000000000 0.80901699437494742410 0.80901699437494742410 -0.30901699437494742410 0.50000000000000000000 0.00000000000000000000 0.30901699437494742410 0.80901699437494742410 0.00000000000000000000 0.50000000000000000000 -0.50000000000000000000 0.00000000000000000000 0.80901699437494742410 0.30901699437494742410 0.00000000000000000000 -0.50000000000000000000 -0.30901699437494742410 0.80901699437494742410