Finite-rank complex deformations of random band matrices: sigma-model approximation

Abstract

We study the distribution of complex eigenvalues $z_1,\dots ,z_N$ of random Hermitian $N\times N$ block band matrices with a complex deformation of a finite rank. Assuming that the width of the band $W$ grows faster than $\sqrt{N}$, we proved that the limiting density of $\Im z_1,\dots ,\Im z_N$ in a sigma-model approximation coincides with that for the Gaussian Unitary Ensemble. The method follows the techniques of arXiv:1802.03813

30 pp. arXiv admin note: substantial text overlap with arXiv:1802.03813