Tolokonnikov’s Lemma for Real H∞ and the Real Disc AlgebraComplex Analysis and Operator Theory - Tập 1 - Trang 439-446 - 2007
Kalle Mikkola, Amol Sasane
We prove Tolokonnikov’s Lemma and the inner-outer factorization for the real Hardy space
$${{H^{\infty}_{\mathbb{R}}}}$$
, the space of bounded holomorphic (possibly operator-valued) functions on the unit disc all of whose matrix-entries (with respect to fixed orthonormal bases) are functions having re...... hiện toàn bộ
Representable Projections and Semi-Projections in a Hilbert SpaceComplex Analysis and Operator Theory - Tập 15 - Trang 1-28 - 2021
J. -Ph. Labrousse
Let
$$H = {\mathcal H}\oplus {\mathcal K}$$
be the direct sum of two Hilbert spaces. In this paper we characterise the semi-projections (defined in the paper) and projections with a given kernel and a given range that can be described by a two by two matrix or block of relations determined by the ...... hiện toàn bộ
Về giả thuyết BMV cho ma trận 2 $$\times $$ 2 và tính lồi theo cấp số mũ của hàm $${\cosh (\sqrt{at^2+b})}$$ Dịch bởi AI Complex Analysis and Operator Theory - Tập 11 - Trang 843-855 - 2015
Victor Katsnelson
Giả thuyết BMV cho rằng đối với các ma trận Hermitian $$n\times n$$ $$A$$ và $$B$$, hàm $$f_{A,B}(t)={{\mathrm{trace\,}}}e^{tA+B}$$ có tính lồi theo cấp số mũ. Gần đây, giả thuyết BMV đã được Herbert Stahl chứng minh. Chứng minh của Herbert Stahl dựa trên những xem xét tinh vi liên quan đến mặt Riemann của các hàm đại số. Trong bài báo này, chúng tôi đưa ra một chứng minh hoàn toàn "ma trận" của g...... hiện toàn bộ
Isometric Equivalence of Integration OperatorsComplex Analysis and Operator Theory - Tập 4 - Trang 245-255 - 2009
Nadia J. Gal, James E. Jamison, Aristomenis G. Siskakis
We are interested in the isometric equivalence problem for the Cesàro operator
$${C(f) (z) =\frac{1}{z} \int_{0}^{z}f(\xi) \frac{1}{1-\xi}d \xi}$$
and an operator
$${T_{g}(f)(z)=\frac{1}{z}\int_{0}^{z}f(\xi) g^{\prime}(\xi) d \...... hiện toàn bộ
Fredholm and Frame-Preserving Weighted Composition OperatorsComplex Analysis and Operator Theory - Tập 18 - Trang 1-13 - 2024
Jasbir Singh Manhas, Ruhan Zhao
We characterize Fredholm and frame-preserving weighted composition operators on some general Hilbert spaces of holomorphic functions in bounded domains in
$${\mathbb {C}}^n$$
.
Extension of the Bessmertnyĭ Realization Theorem for Rational Functions of Several Complex VariablesComplex Analysis and Operator Theory - - 2021
Anthony Stefan, Aaron Welters
We prove a realization theorem for rational functions of several complex variables which extends the main theorem of Bessmertnyĭ (in: Alpay, Gohberg, Vinnikov (eds) Interpolation Theory, Systems Theory and Related Topics. Operator Theory Advances and Applications vol 134. Birkhauser Verlag, Basel, pp 157–185, 2002). In contrast to Bessmertnyĭ’s approach of solving large systems of linear equations...... hiện toàn bộ
The Singular Integral Operator Induced by Drury–Arveson KernelComplex Analysis and Operator Theory - Tập 12 - Trang 917-929 - 2016
Guozheng Cheng, Xiaoyang Hou, Chao Liu
In this paper, we study the singular integral operator induced by the reproducing kernel of the Drury–Arveson space
$$\begin{aligned} Kf(z) =\int _{\mathbb {B}_n} k(z, w) f(w) dv(w), \end{aligned}$$
where
...... hiện toàn bộ