テンソル
vector = 1st order tensor
contravariant vector
v ∈ V
covariant vector
f ∈ V*
種別
0階のテンソル (0th order)
1階のテンソル (1st order)
en: 1st order tensor
covariant tensor
ja: 共変テンソル
= covariant vector
contravariant tensor
ja: 反変テンソル
= contravariant vector
e.g. 座標 $ x^μ
2階のテンソル (2nd order)
2nd order covariant tensor
2nd order contravariant tensor
2nd order mixed tensor
演算
テンソル積 ⊗
ref.