Almost Mathieu operator 1 Bargmann space 1 Benjamin–Ono equation 1 Bochner Laplacian 1 Cauchy data 1 Dirichlet eigenvalues 1 Dirichlet-to-Neumann map 1 Eigenvalue distribution 1 FBI transform 1 Gevrey pseudodifferential operator 1 Haynsworth formula 1 Laplace–Beltrami operator 1 Laplacian 1 Morse index 1 Pseudodifferential projections 1 Robin eigenvalues 1 Schur complement 1 Semiclassical analysis 1 Spectral projector 1 Spectral rigidity 1 Spectral shift 1 Symplectic manifold 1 Toeplitz operators 1 Weyl estimates 1 action to frequency map 1 almost holomorphic extension 1 almost periodic 1 asymptotics 1 billiards 1 coherent states 1