previous | top | next

Derivatives in Flat, Euclidean Spacetime

4-derivatives: time and 3-space derivatives in a rank-1 tensor.

Signs of covariant and contravariant derivatives flip (arg!). The asymmetric rank-2 tensor that results from taking the 4-derivative of a 4-vector can be represented by the symmetric average amount of change tensor plus the antisymmetric deviation of change tensor.

Slide 26 stands for freedom constraints.