Acta Mathematica Academiae Scientiarum Hungarica - Tập 168 - Trang 443-453 - 2022
P. Kumar
The Erdős–Lax Theorem states that, if P(z) is a polynomial of degree n having no zeros in
$$|z|<1$$
, then
$$\max_{|z|=1}|P'(z)|\leq \frac{n}{2}\max_{|z|=1}|P(z)|.$$
The problem of generaliz...... hiện toàn bộ
Acta Mathematica Academiae Scientiarum Hungarica - Tập 84 - Trang 267-274 - 1999
I. Joó, Nguyen Van Su
This paper is concerned with the null-controllability of the infinite-dimensional discrete-time linear system described by
$$(A, B, \Omega ) x_{n + 1} = Ax_n + Bu_n$$
where xn ∈ X, un ∈ Ω ⊂ U, X and U are Asplund spaces, A ∈ L(X, X), B ∈ L (U, X), Ω is a convex set, int Ω ≠ 0 and 0 ∈ Ω.