| 释义 |
Direct Product (Tensor)For a first-Rank Tensor (i.e., a Vector),
 | (1) |
which is a second-Rank Tensor. The Contraction of adirect product of first-Rank Tensors is the Scalar
 | (2) |
For a second-Rank Tensor,
 | (3) |
 | (4) |
For a general Tensor, the direct product of two Tensors is a Tensor of Rank equal to the sum ofthe two initial Ranks. The direct product is Associative, but not Commutative. References
Arfken, G. ``Contraction, Direct Product.'' §3.2 in Mathematical Methods for Physicists, 3rd ed. Orlando, FL: Academic Press, pp. 124-126, 1985. |