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On Szegö’s asymptotic formula for Toeplitz determinants and generalizations. (English) Zbl 0661.30001
A new proof was given for the asymptotic formula for the Toeplitz $$\det er\min ant:$$
D$${}_{n-1}(f)=\exp (nc_ 0+\sum^{\infty}_{k=1}kc_ kc_{- k}+o(1))$$ as $$n\to \infty$$ $$(c_ k$$ are complex Fourier coefficients of log f), proved earlier by G. Szegö [Meddel. Lunds Univ. Mat. Sem. Suppl.-Band M. Riesz, 228-238 (1952; Zbl 0048.042)]. The formula was proved in the first part for complex valued f under the assumption $$\sum^{\infty}_{-\infty}| k| | c_ k|^ 2$$, using the well-known integral representation of a Toeplitz determinant as a basis. In the second part an asymptotic formula for Hankel determinants was $$proved:$$
D$${}_{n-1}(f)D_{n-1}(1)^{-1}=\exp (na_ 0+(1/8)\sum^{\infty}_{k=1}ka^ 2_ k+o(1))$$ as $$n\to \infty$$, $$a_ k$$ are the coefficients in the expansion of f in Chebyshev polynomials. Finally a similar formula was proved for a determinant being a function on $$\gamma$$ ($$\gamma$$ is a Jordan curve in the complex plane).
Reviewer: V.Burjan

##### MSC:
 30C15 Zeros of polynomials, rational functions, and other analytic functions of one complex variable (e.g., zeros of functions with bounded Dirichlet integral) 47B35 Toeplitz operators, Hankel operators, Wiener-Hopf operators
##### Keywords:
Toeplitz operators; Toeplitz determinant