# Eigenvalues of Hermitian Toeplitz matrices with polynomially increasing entries

### Johan M. Bogoya

Pontificia Universidad Javeriana, Bogota, Colombia### Albrecht Böttcher

Technische Universität Chemnitz, Germany### Alexander Poznyak

CINVESTAV del IPN, Mexico, D.F., Mexico

## Abstract

The paper is concerned with finite Hermitian Toeplitz matrices whose entries in the first row grow like a polynomial. Such matrices cannot be viewed as truncations of an infinite Toeplitz matrix which is generated by an integrable function or a nice measure. The main results describe the first-order asymptotics of the extreme eigenvalues as the matrix dimension goes to infinity and also deliver unexpected barriers for the eigenvalues. One purpose of the paper is to popularize once more that questions on the eigenvalues of matrices can be answered in a very elegant way by passing to integral operators. This idea was introduced by Harold Widom about fifty years ago. In this way one can also give an alternative proof to results by William F. Trench on Hermitian Toeplitz matrices with increasing entries.

## Cite this article

Johan M. Bogoya, Albrecht Böttcher, Alexander Poznyak, Eigenvalues of Hermitian Toeplitz matrices with polynomially increasing entries. J. Spectr. Theory 2 (2012), no. 3, pp. 267–292

DOI 10.4171/JST/29