Covariant Derivative
The covariant derivative of a contravariant tensor A^a (also called the "semicolon derivative" since its symbol is a semicolon) is given by
(Weinberg 1972, p. 103), where Gamma_(ij)^k is a Christoffel symbol, Einstein summation has been used in the last term, and A_(,k)^k is a comma derivative. The notation del ·A, which is a generalization of the symbol commonly used to denote the divergence of a vector function in three dimensions, is sometimes also used.
The covariant derivative of a covariant tensor A_a is
(Weinberg 1972, p. 104).
Schmutzer (1968, p. 72) uses the older notation A^j_(∥k) or A_(j∥k).
See also
Christoffel Symbol, Comma Derivative, Covariant Tensor, Divergence, Levi-Civita ConnectionExplore with Wolfram|Alpha
More things to try:
References
Morse, P. M. and Feshbach, H. Methods of Theoretical Physics, Part I. New York: McGraw-Hill, pp. 48-50, 1953.Schmutzer, E. Relativistische Physik (Klassische Theorie). Leipzig, Germany: Akademische Verlagsgesellschaft, 1968.Weinberg, S. "Covariant Differentiation." §4.6 in Gravitation and Cosmology: Principles and Applications of the General Theory of Relativity. New York: Wiley, pp. 103-106, 1972.Referenced on Wolfram|Alpha
Covariant DerivativeCite this as:
Weisstein, Eric W. "Covariant Derivative." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/CovariantDerivative.html