^{2}=\mathrm {d} \theta ^{2}+\sin ^{2}\theta \mathrm {d} \varphi ^{2}\,} 是二維球面(2-sphere)上的標準度規(即:立體角的標準單元)。 定義 r s = 2 G M c 2 {\displaystyle r_{s}={\frac {2GM}{c^{2}}}}
= a d − b c {\displaystyle qq^{*}=ad-bc} ,矩阵的行列式。因此,反四元数的单位拟球(英语:Quasi-sphere)与 S L ( 2 , R ) = { g ∈ M ( 2 , R ) : det g = 1 } {\displaystyle SL(2,\mathbb
a Windows application for converting Munsell renotations to CIELAB coordinates. Munsell Color Science Laboratory(页面存档备份,存于互联网档案馆) at the Rochester Institute
barycentric coordinates. Select Ephemeris Type:Elements and Center:@0) Kaler, James B. The ever-changing sky: a guide to the celestial sphere. Cambridge