24 citations · 28 across the 3 of their papers we have counts for
3 papers
math-ph2025
Local perturbations of block Toeplitz matrices
Lars Koekenbier, Hermann Schulz-Baldes
This work is about the asymptotic spectral theory of tridiagonal Toeplitz matrices with matrix entries, with periodicity broken on a finite number of entries. Varying the ranks of…
math-ph2024★ 4 cited
Transfer matrix analysis of non-hermitian Hamiltonians: asymptotic spectra and topological eigenvalues
Lars Koekenbier, Hermann Schulz-Baldes
Transfer matrix techniques are used to provide a new proof of Widom's results on the asymptotic spectral theory of finite block Toeplitz matrices. Furthermore, a rigorous treatment…
math-ph2023★ 24 cited
Spectral localizer for line-gapped non-hermitian systems
Alexander Cerjan, Lars Koekenbier, Hermann Schulz-Baldes
Short-ranged and line-gapped non-hermitian Hamiltonians have strong topological invariants given by an index of an associated Fredholm operator. It is shown how these invariants ca…