Wolfgang Strößner (now Wolfgang Schaper): Zur Spektralgeometrie singulärer algebraischer Kurven.
(Berlin 1998, supervised jointly with Jochen Brüning), Wolfgang Schaper now works as Senior product manager for NTT Data solutions
Christian Frey: On non-local boundary value problems for elliptic operators,
Köln 2005
Boris Vertman:
The Analytic Torsion for Manifolds with Boundary and Conical Singularities.
Bonn, 2008. Geometry and Topology 13, no. 4, 1989--2027 (2009).
math.DG/0808.0416
Michael Bohn:
On rho invariants of fiber bundles. Bonn, 2009.
math.GT/0907.3530
Carolina Neira Jimenez:
Cohomology Of Classes Of Symbols And Classification Of Traces On Corresponding Classes Of Operators With Non Positive Order. Bonn, 2010.
J. Noncommut. Geom. 7 (2013), 457-498.
math.OA/10113238.