Complete asymptotic expansion of a spectral function of elliptic operators in $R^n$

The paper gives a complete asymptotic expansion as $\lambda\to\infty$, $|x|,|y|\le b<\infty$ of a spectral function $e_\lambda(x,y)$ of elliptic operators of the second order in $R^n$ for which the “non-trapping mode” condition is fulfilled, i. е., bicharacteristics emergent from any point extend to infinity.