Formula_4112

\[\begin{gathered}I(\tau)=\varphi(0)(2 \pi / \tau)^{n / 2} \exp \left(i \tau f(0)+(i \pi / 4)\left(\operatorname{sign} f_{x x}^{\prime \prime}(0)\right)\right) \times \\\times\left|\operatorname{det} f_{x x}^{\prime \prime}(0)\right|^{-1 / 2}+O\left(\tau^{-n / 2-1}\right)\end{gathered}\]