8 papers
Universal algorithms for computing spectra of periodic operators
Jonathan Ben-Artzi, Marco Marletta, Frank Rösler
Schrödinger operators with periodic (possibly complex-valued) potentials and discrete periodic operators (possibly with complex-valued entries) are considered, and in both cases th…
Computing the Sound of the Sea in a Seashell
Jonathan Ben-Artzi, Marco Marletta, Frank Rösler
The question of whether there exists an approximation procedure to compute the resonances of any Helmholtz resonator, regardless of its particular shape, is addressed. A positive a…
Computing Scattering Resonances
Jonathan Ben-Artzi, Marco Marletta, Frank Rösler
The question of whether it is possible to compute scattering resonances of Schrödinger operators - independently of the particular potential - is addressed. A positive answer is gi…
Essential numerical ranges for linear operator pencils
Sabine Bögli, Marco Marletta
We introduce concepts of essential numerical range for the linear operator pencil . In contrast to the operator essential numerical range, the pencil essential numer…
The essential numerical range for unbounded linear operators
Sabine Bögli, Marco Marletta, Christiane Tretter
We introduce the concept of essential numerical range for unbounded Hilbert space operators and study its fundamental properties including possible equivalent char…
Essential spectrum for Maxwell's equations
Giovanni S. Alberti, Malcolm Brown, Marco Marletta +1
We study the essential spectrum of operator pencils associated with anisotropic Maxwell equations, with permittivity , permeability and conductivity , on finite…