Ψ ( x _ , t ) = ( 2 π ) − d ╱ 2 ∫ φ ( k _ ) e − ω ( k _ ) t + k _ . x _ d d k _ {\displaystyle \Psi \left({\underline {x}},t\right)={{\left(2\pi \right)}^{-{}^{d}\!\!\diagup \!\!{}_{2}\;}}\int {\varphi \left({\underline {k}}\right){{e}^{-\omega \left({\underline {k}}\right)t+{\underline {k}}.{\underline {x}}}}{{d}^{d}}{\underline {k}}}} d Raumdimension
ω ( k _ ) = k _ 2 + m 2 {\displaystyle \omega \left({\underline {k}}\right)={\sqrt {{\underline {k}}^{2}+{m}^{2}}}}
d Raumdimension
