Formula_19116

\[f(t, \rho, v)=\frac{12}{\pi^{2} t^{2}\left(v^{2}\right)^{2}} \exp \left\{-\frac{4}{v^{2}}\left(v^{2}+\frac{3 \rho^{2}}{t^{2}}-\frac{3 v \rho}{t}\right)\right\},\]