Agranovich, M. S.; Amosov, B. A. On Fourier series in eigenfunctions of elliptic boundary value problems. (English) Zbl 1050.35054 Georgian Math. J. 10, No. 3, 401-410 (2003). The authors consider an elliptic \(bvp\) of order \(2m\) of the form \[ A(x,D)u(x)=f(x)\in \Omega \]\[ B_j(x,D)u(x)=0\text{ on }\partial \Omega,\;j=1,\dots,m. \] The coefficients of \(A\) and \(B\) are assumed to be smooth in \(\overline\Omega\) and \(\partial\Omega\). The authors discuss convergence of eigenfunctions in \(H^t(\Omega)\). Reviewer: René Sperb (Zürich) Cited in 2 Documents MSC: 35P05 General topics in linear spectral theory for PDEs 35J55 Systems of elliptic equations, boundary value problems (MSC2000) 42C15 General harmonic expansions, frames 46B15 Summability and bases; functional analytic aspects of frames in Banach and Hilbert spaces Keywords:convergence of eigenfunctions PDFBibTeX XMLCite \textit{M. S. Agranovich} and \textit{B. A. Amosov}, Georgian Math. J. 10, No. 3, 401--410 (2003; Zbl 1050.35054) Full Text: EuDML