Wightman function
= Wightman function
{wiki}
A Wightman function is an unordered vacuum correlation function. For a free scalar mode $f_k(t)$, the positive-frequency two-point function is $G^>(t_1,t_2;k)=f_k(t_1)f_k^*(t_2)$.
= Wightman function
{wiki}
A Wightman function is an unordered vacuum correlation function. For a free scalar mode $f_k(t)$, the positive-frequency two-point function is $G^>(t_1,t_2;k)=f_k(t_1)f_k^*(t_2)$.