Zobrazeno 1 - 10
of 330
pro vyhledávání: '"Mashreghi Javad"'
Publikováno v:
Special Matrices, Vol 12, Iss 1, Pp 635-655 (2024)
The geometry of the compact convex set of all n×nn\times n doubly stochastic matrices, a structure frequently referred to as the Birkhoff polytope, has been an active subject of research as of late. Geometric characteristics such as the Chebyshev ce
Externí odkaz:
https://doaj.org/article/52d90300187d4022b0baaa52ce2abb81
We conduct a spectral analysis of the difference quotient operator $Q^u_\zeta$, associated with a boundary point $\zeta \in \partial \mathbb{D}$, on the model space $K_u$. We describe the operator's spectrum and provide both upper and lower estimates
Externí odkaz:
http://arxiv.org/abs/2410.18623
The family of Ces\`{a}ro operators $\sigma_n^\alpha$, $n \geq 0$ and $\alpha \in [0,1]$, consists of finite rank operators on Banach spaces of analytic functions on the open unit disc. In this work, we investigate these operators as they act on the l
Externí odkaz:
http://arxiv.org/abs/2410.00828
The Crouzeix ratio $\psi(A)$ of an $N\times N$ complex matrix $A$ is the supremum of $\|p(A)\|$ taken over all polynomials $p$ such that $|p|\le 1$ on the numerical range of $A$. It is known that $\psi(A)\le 1+\sqrt{2}$, and it is conjectured that $\
Externí odkaz:
http://arxiv.org/abs/2409.14127
Given a compact convex planar domain $\Omega$ with non-empty interior, the classical Neumann's configuration constant $c_{\mathbb{R}}(\Omega)$ is the norm of the Neumann-Poincar\'e operator $K_\Omega$ acting on the space of continuous real-valued fun
Externí odkaz:
http://arxiv.org/abs/2407.19049
For a given unitary operator $U$ on a separable complex Hilbert space $\h$, we describe the set $\mathscr{C}_{c}(U)$ of all conjugations $C$ (antilinear, isometric, and involutive maps) on $\h$ for which $C U C = U$. As this set might be empty, we al
Externí odkaz:
http://arxiv.org/abs/2402.14997
In this paper, we address the problem of recovering constant source terms in a discrete dynamical system represented by $x_{n+1} = Ax_n + w$, where $x_n$ is the $n$-th state in a Hilbert space $\mathcal{H}$, $A$ is a bounded linear operator in $\math
Externí odkaz:
http://arxiv.org/abs/2401.15450
Publikováno v:
Concrete Operators, Vol 4, Iss 1, Pp 76-108 (2017)
This paper is selective survey on the space lAp and its multipliers. It also includes some connections of multipliers to Birkhoff-James orthogonality
Externí odkaz:
https://doaj.org/article/264b62ade67a4a79a4599542078b4680
In the first of this series of two articles, we studied some geometrical aspects of the Birkhoff polytope, the compact convex set of all $n \times n$ doubly stochastic matrices, namely the Chebyshev center, and the Chebyshev radius of the Birkhoff po
Externí odkaz:
http://arxiv.org/abs/2310.14043
The geometry of the Birkhoff polytope, i.e., the compact convex set of all $n \times n$ doubly stochastic matrices, has been an active subject of research. While its faces, edges and facets as well as its volume have been intensely studied, other geo
Externí odkaz:
http://arxiv.org/abs/2310.14041