We systematically develop Weyl-Titchmarsh theory for singular differential operators on
arbitrary intervals $(a, b)\subseteq\mathbb {R} $ associated with rather general differential …

We discuss direct and inverse spectral theory for the isospectral problem of the
dispersionless Camassa–Holm equation, where the weight is allowed to be a finite signed …

The inverse quantum scattering problem for the perturbed Bessel equation is considered. A
direct and practical method for solving the problem is proposed. It allows one to reduce the …

Building on work on Miura's transformation by Kappeler, Perry, Shubin, and Topalov, we
develop a detailed spectral theoretic treatment of Schrödinger operators with matrix-valued …

Based on continuity properties of the de Branges correspondence, we develop a new
approach to study the high-energy behavior of Weyl–Titchmarsh and spectral functions of 2× …

In this paper we introduce an index $\ell_c\in\mathbb {N} _0\cup\lbrace\infty\rbrace $ which
we call theregularization index'associated to the endpoints, $ c\in\{a, b\} $, of nonoscillatory …

Abstract We develop singular Weyl–Titchmarsh–Kodaira theory for one-dimensional Dirac
operators. In particular, we establish existence of a spectral transformation as well as local …

We investigate the dependence of the $ L^ 1\to L^\infty $ dispersive estimates for one-
dimensional radial Schr\" o\-din\-ger operators on boundary conditions at $0 $. In contrast to …

The present work aims at obtaining estimates for transformation operators for one-
dimensional perturbed radial Schrödinger operators. It provides more details and suitable …

We derive a dispersion estimate for one-dimensional perturbed radial Schrödinger
operators. We also derive several new estimates for solutions of the underlying differential …