\[\sigma\left(\omega_{2}\right)=-2\omega_{1}\frac{\exp\left(\tfrac{1}{2}\eta_{1}%
(\omega_{1}\tau^{2}+\omega_{3}-\omega_{2})\right)\theta_{3}\left(0,q\right)}{%
\pi q^{1/4}\theta_{1}'\left(0,q\right)},\]