Recent content by dhalilsim

I obtained the black hole solution whose the metric function f(r) and scalar function ##\varphi(r)## are ; ##f(r)=\frac{1}{4}+\left(\frac{Z^{2}}{2r^{2}}\right)^{2}-\frac{1}{3}\Lambda r^{2}## ##\varphi(r)=\pm\left(\frac{1}{\sqrt{2}l}\right)r## where ##Z##, ##\Lambda## and ##l## are just...

Very thanks to your reply. Yes my question is whether or not ##∇_μ∇_ν∇^νF_{ab}=∇_ν∇^ν∇_μF_{ab}## where ##F_{ab}## is electromagnetic field tensor. Can I simply think, so d'Alembert operator ##∇_ν∇^ν## is invariant, then Can I immediately write ##[∇_μ,\Box]=0##??

For example: [itex] D_α D_β D^β F_ab= D_β D^β D_α F_ab is true or not? Are there any books sources?