Several seemingly unrelated linear operators appearing in mathematical physics exhibit similarities in their spectral structure, which is characterized by a particular non-trivial essential spectrum. Examples come from electrodynamics, elasticity theory and fluid dynamics. The point of view of selfadjoint extensions can clarify their relations. In the talk I show recent results about these spectra and explain several open questions.
Joint work with Eric Darrigrand, El-Hadji Koné, Hamdi Sakly, Monique Dauge, Michel Crouzeix.
Due to technical problems with the microphone, the sound of this video may be partially or completely scrambled, we apologize for this.