- #1
Umaxo
- 51
- 12
Hi,
I know that principal null directions are defined as vector at a point that satisfy the equation ##k_{[a}C_{b]cd[e}k_{f]}k^ck^d=0##, where ##C_{abcd}## is weyl tensor. I know they are used for generating solutions to einstein equations and that they are used for algebraic classification of solutions to einstein field equations.
What i cannot find anywhere is some explanation on their geometrical meaning. Do you know what is their geometrical meaning if they have any? - Something one could visualize. Do you know some literature where I could read more about them?
Thanks:)
I know that principal null directions are defined as vector at a point that satisfy the equation ##k_{[a}C_{b]cd[e}k_{f]}k^ck^d=0##, where ##C_{abcd}## is weyl tensor. I know they are used for generating solutions to einstein equations and that they are used for algebraic classification of solutions to einstein field equations.
What i cannot find anywhere is some explanation on their geometrical meaning. Do you know what is their geometrical meaning if they have any? - Something one could visualize. Do you know some literature where I could read more about them?
Thanks:)