Spectral theory for symmetric systems in an exterior domain. II (Q1118793)

In a previous paper [Tsukuba J. Math. 11, 241-256 (1987; Zbl 0655.35059)], the author studied the spectral theory for symmetric systems with certain ceorcive boundary condition on an unbounded domain with boundary \(\Gamma =\{x\in {\mathbb{R}}^ n:| x| =\rho (x)\}\), where \(\rho\) is a positively homogeneous \(C^{\infty}({\mathbb{R}}^ n\setminus \{0\})\)-function. In the present paper, analogous results are proved without any restriction on the shape of \(\Gamma\).