Non-Bloch band theory for finite banded non-Hermitian Toeplitz matrices
My Interests
My current research concerns subwavelength wave propagation in periodic media governed by the Helmholtz equation. My approach is to describe the leading-order asymptotics with the so-called capacitance matrix, and to exploit its Toeplitz-like structure to analyse the spectrum and the localisation of eigenmodes, in both Hermitian and non-Hermitian settings.
Short CV
I am a PhD student in Computational and Applied Mathematics at the University of Oslo, supervised by Prof. Erik Orvehed Hiltunen. Before that, I did my master's degree at ETH Zurich under the supervision of Prof. Habib Ammari, during which I was also a Visiting Scholar in Applied Mathematics at Yale University. In 2026 I was awarded the MetaMAT Medal in Ajaccio.
Publications
Topologically protected interface modes in multi-band damped lattice models
Mathematical Foundation for the Generalised Brillouin zone of m-banded Toeplitz operators
Spectra and pseudospectra of non-Hermitian Toeplitz operators: Eigenvector decay transitions in banded and dense matrices
Complex Band Structure and localisation transition for tridiagonal non-Hermitian k-Toeplitz operators with defects
Complex Brillouin Zone for Localised Modes in Hermitian and Non-Hermitian Problems
Complex Band Structure for Subwavelength Evanescent Waves
Spectra and pseudo-spectra of tridiagonal k-Toeplitz matrices and the topological origin of the non-Hermitian skin effect
Invited Talks
Toeplitz theory meets metamaterials
Wave scattering in periodic media
Wave localisation in periodic media
Complex Band Structure in the Spectral Theory of Toeplitz Operators and Applications to Metamaterials
Contact
University of Oslo
Moltke Moes vei 35
0851 Oslo
Norway
Office: NHA 1004
Email: yannicd@math.uio.no
My Departmental Page
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