## Absolute continuity of the spectrum of a two-dimensional Schrödinger operator with potential supported on a periodic system of curves.(English. Russian original)Zbl 0998.35006

St. Petersbg. Math. J. 12, No. 6, 983-1012 (2001); translation from Algebra Anal. 12, No. 6, 140-177 (2001).
Summary: The present paper is a continuation of M. Sh. Birman and T. A. Suslina [Two-dimensional periodic magnetic Hamiltonian is absolutely continuous, Algebra Anal. 9, No. 1, 32-48 (1997); translated in St. Petersbg. Math. J. 9, No. 1, 21-32 (1998; Zbl 0890.35096)]. Absolute continuity of the two-dimensional periodic magnetic Hamiltonian with discontinuous vector-valued potential, Algebra Anal. 10, No. 4, 1-36 (1998); translated in St. Petersbg. Math. J. 10, No. 4, 579-601 (1999; Zbl 0922.35101] Periodic magnetic Hamiltonian with variable metric. The problem of absolute continuity, Algebra Anal. 11, No. 2, 1-40 (1999); translated in St. Petersbg. Math. J. 11, No. 2, 203-232 (2000; Zbl 0941.35015)]. A two-dimensional periodic magnetic Schrödinger operator with variable metric is considered. The electric potential is assumed to contain a term proportional to the $$\delta$$-function supported on a periodic system of piecewise-smooth curves. It is shown that, under rather general assumptions on the problem data, the spectrum of the Schrödinger operator is absolutely continuous.

### MSC:

 35J10 Schrödinger operator, Schrödinger equation 35P15 Estimates of eigenvalues in context of PDEs 35P05 General topics in linear spectral theory for PDEs

### Citations:

Zbl 0890.35096; Zbl 0922.35101; Zbl 0941.35015