On the Fourier coefficients of powers of a Blaschke factor and strongly annular functions
A Borichev, K Fouchet, R Zarouf - Constructive Approximation, 2024 - Springer
We compute asymptotic formulas for the k th Fourier coefficients of b λ n, where b λ (z)= z-λ 1-
λ z is the Blaschke factor associated to λ∈ D, k∈[0,∞) and n is a large integer. We …
λ z is the Blaschke factor associated to λ∈ D, k∈[0,∞) and n is a large integer. We …
[HTML][HTML] Analytic capacities in Besov spaces
We derive new estimates on analytic capacities of finite sequences in the unit disc in Besov
spaces with zero smoothness, which sharpen the estimates obtained by NK Nikolski in 2005 …
spaces with zero smoothness, which sharpen the estimates obtained by NK Nikolski in 2005 …
On the asymptotic behavior of Jacobi polynomials with first varying parameter
We investigate the large n behavior of Jacobi polynomials with varying parameters P n (a n+
α, b n+ β)(1− 2 λ 2) for a, b>− 1 and λ∈(0, 1). This is a well-studied topic in the literature but …
α, b n+ β)(1− 2 λ 2) for a, b>− 1 and λ∈(0, 1). This is a well-studied topic in the literature but …
On the Fourier coefficients of powers of a finite Blaschke product
A Borichev, K Fouchet, R Zarouf - International Mathematics …, 2024 - academic.oup.com
Given a finite Blaschke product we prove asymptotically sharp estimates on the-norm of the
sequence of the Fourier coefficients of as tends to. This norm decays as for some …
sequence of the Fourier coefficients of as tends to. This norm decays as for some …
On the condition number of a Kreiss matrix
S Charpentier, K Fouchet, R Zarouf - Canadian Mathematical Bulletin, 2023 - cambridge.org
In 2005, N. Nikolski proved among other things that for any $ r\in (0, 1) $ and any $ K\geq 1$,
the condition number $ CN (T)=\Vert T\Vert\cdot\Vert T^{-1}\Vert $ of any invertible n …
the condition number $ CN (T)=\Vert T\Vert\cdot\Vert T^{-1}\Vert $ of any invertible n …
Stationary phase method, powers of functions, and applications to functional analysis
H Queffélec, R Zarouf - St. Petersburg Mathematical Journal, 2023 - ams.org
The utility of the (weighted) van der Corput inequalities or of the stationary phase method is
illustrated with various examples borrowed from: differentiability issues (Riemann's function …
illustrated with various examples borrowed from: differentiability issues (Riemann's function …
Condition numbers of matrices with given spectrum
This note surveys recent strategies to estimate the condition number CN (T)= ‖ T ‖ ⋅ ‖ T^-
1 ‖ CN (T)=‖ T‖·‖ T-1‖ of complex n * nn× n matrices T with given spectrum. More …
1 ‖ CN (T)=‖ T‖·‖ T-1‖ of complex n * nn× n matrices T with given spectrum. More …