An example of multiple gaps in the spectrum of a periodic waveguide. (English. Russian original) Zbl 1193.35038

Nazarov, S. A.

Sb. Math. 201, No. 4, 569-594 (2010); translation from Mat. Sb. 201, No. 4, 99-124 (2010).

MSC:

35J57	Boundary value problems for second-order elliptic systems
35J20	Variational methods for second-order elliptic equations
35P15	Estimates of eigenvalues in context of PDEs
78A50	Antennas, waveguides in optics and electromagnetic theory

Keywords:

gaps in the essential spectrum; formally self-adjoint elliptic system of differential equations with polynomial property