11 papers
The uniqueness of the spectral flow on spaces of unbounded self--adjoint Fredholm operators
Matthias Lesch
We discuss several natural metrics on spaces of unbounded self--adjoint operators and their relations, among them the Riesz and the graph metric. We show that the topologies of the…
Calderon projector for the Hessian of the perturbed Chern-Simons function on a 3-manifold with boundary
Benjamin Himpel, Paul Kirk, Matthias Lesch
The existence and continuity for the Calderon projector of the perturbed odd signature operator on a 3-manifold is established. As an application we give a new proof of a result of…
Unbounded Fredholm Operators and Spectral Flow
Bernhelm Booss-Bavnbek, Matthias Lesch, John Phillips
We study the gap (= "projection norm" = "graph distance") topology of the space of (not necessarily bounded) self--adjoint Fredholm operators in a separable Hilbert space by the Ca…
On the number of square integrable solutions and self-adjointness of symmetric first order systems of differential equations
Matthias Lesch, Mark M. Malamud
The main purpose of this paper is to investigate the formal deficiency indices of a symmetric first order system on an interval , wh…
The eta-invariant, Maslov index, and spectral flow for Dirac-type operators on manifolds with boundary
Paul Kirk, Matthias Lesch
Several proofs have been published of the Mod Z gluing formula for the eta-invariant of a Dirac operator. However, so far the integer contribution to the gluing formula for the eta…
Essential self-adjointness of symmetric linear relations associated to first order systems
Matthias Lesch
The purpose of this note is to present several criteria for essential self-adjointness. The method is based on ideas due to Shubin. This note is divided into two parts. The first p…