The Christoffel-Darboux Kernel

The Damped String Problem Revisited

The Darboux process and a noncommutative bispectral problem

The determinant of the Dirichlet-to-Neumann map for surfaces with boundary

The Dirac-Hardy and Dirac-Sobolev inequalities in $L^1$

The discrete spectrum for complex perturbations of periodic Jacobi matrices

The effective Hamiltonian for thin layers with non-Hermitian Robin-type boundary conditions

The effective Hamiltonian in curved quantum waveguides under mild regularity assumptions

The Eigen-Problem for Some Special Near-Toeplitz Centro-Skew Tridiagonal Matrices

The eigenvalues of the Laplacian on domains with small slits

The essential spectrum of Schrodinger, Jacobi, and CMV operators

The Fundamental Gap Conjecture on Polygonal Domains

The fundamental gap of simplices

The Hardy-Rellich Inequality for Polyharmonic Operators

The Hessenberg matrix and the Riemann mapping

The hybrid spectral problem and Robin boundary conditions

The index formula and the spectral shift function for relatively trace class perturbations

The inverse problem for perturbed harmonic oscillator on the half-line with Dirichlet boundary conditions

The inverse resonance problem for $\Z_2$-symmetric analytic obstacles in the plane

The inverse spectral problem for first order systems on the half line