Meaning of Kronecker delta | Babel Free

Definitions

1. A binary function, written as δ with two subscripts, which evaluates to 1 when its arguments are equal, and 0 otherwise.
2. A unary function, written as δ with a single index, which evaluates to 1 at zero, and 0 elsewhere.

Examples

“The Kronecker delta #92;delta#95;#123;ij#125; is an example of an isotropic tensor. That is, its components remain invariant with rotation of coordinate axes.”

“The permutation symbol and the Kronecker delta prove to be very useful in proving vector identities.”

“The most important property of the Kronecker delta occurs when it shares a common repeated index with another tensor: Note 10.1.3. When an index of a tensor T is contracted with one of the indices of the Kronecker delta, the result is an expression in which the Kronecker delta is removed and the contracted index of T is replaced by the other index of the Kronecker delta.”

CEFR level