■基本単体の二面角(その419)
【7】E7格子の場合
P0(0,0,0,0,0,0,0)
P1(1,0,0,0,0,0,0)
P2(1,1/√3,0,0,0,0,0)
P3(1,1/√3,1/√6,0,0,0,0)
P4(1,1/√3,1/√6,1/√6,0,0,0,0)
P5(1,1/√3,1/√6,1/√6,1/√3,0,0)
P6(1,1/√3,1/√6,1/√6,1/√3,1,0)
P7(1,1/√3,1/√6,0,0,0,1/2)
超平面をax+by+cz+dw+ev+fu+gt=iとする.
[1]P1P2P3P4P5P6P7を通る超平面:x=1
[2]P0P2P3P4P5P6P7を通る超平面
i=0
a+b/√3=0,a=1,b=−√3
1−1+c/√6=0,c=0
1−1+c/√6+d/√6=0,d=0,e=0,f=0
1−1+g/2=0,g=0
[3]P0P1P3P4P5P6P7を通る超平面
i=0,a=0
b/√3+c/√6=0,b=1,c=−√2
b/√3+c/√6+d/√6=0,d=0,e=0,f=0
1−1+g/2=0,g=0
[4]P0P1P2P4P5P6P7を通る超平面
i=0,a=0,b=0
c/√6+d/√6=0,c=1,d=−1
e=0,f=0
c/√6+g/2=0,g=−2/√6
[5]P0P1P2P3P5P6P7を通る超平面
i=0,a=0,b=0,c=0
d/√6+e/√3=0,d=√2,e=−1
f=0,g=0
[6]P0P1P2P3P4P6P7を通る超平面
i=0,a=0,b=0,c=0,d=0
e/√3+f=0,e=√3,f=−1,g=0
[7]P0P1P2P3P4P5P7を通る超平面:u=0
[8]P0P1P2P3P4P5P6を通る超平面:t=0
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a=(1,0,0,0,0,0,0)
b=(1,−√3,0,0,0,0,0)
c=(0,1,−√2,0,0,0,0)
d=(0,0,1,−1,0,0,−2/√6)
e=(0,0,0,√2,−1,0,0)
f=(0,0,0,0,√3,−1,0)
g=(0,0,0,0,0,1,0)
h=(0,0,0,0,0,0,1)
を正規化すると
a=(1,0,0,0,0,0,0)
b=(1/2,−√3/2,0,0,0,0,0)
c=(0,1/√3,−√(2/3),0,0,0,0)
d=(0,0,√6/4,−√6/4,0,0,−1/2)
e=(0,0,0,√(2/3),−1/√3,0,0)
f=(0,0,0,0,√3/2,−1/2,0)
g=(0,0,0,0,0,1,0)
h=(0,0,0,0,0,0,1)
a・b=1/2
b・c=−1/2
c・d=−1/2
d・e=−1/2
d・h=−1/2
e・f=−1/2
f・g=−1/2
g・h=0
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