Results 1 to 10 of about 582,641 (301)

The invariant subspaces of S ⊕ S *

Concrete Operators, 2020
Using the tools of Sz.-Nagy–Foias theory of contractions, we describe in detail the invariant subspaces of the operator S ⊕ S*, where S is the unilateral shift on a Hilbert space. This answers a question of Câmara and Ross.
Dan Timotin
exaly   +3 more sources

The closedness of shift invariant subspaces in Lp,q(Rd+1) $L^{p,q} (\mathbb{R}^{d+1} )$ [PDF]

Journal of Inequalities and Applications, 2018
In this paper, we consider the closedness of shift invariant subspaces in Lp,q(Rd+1) $L^{p,q} (\mathbb{R}^{d+1} )$. We first define the shift invariant subspaces generated by the shifts of finite functions in Lp,q(Rd+1) $L^{p,q} (\mathbb{R}^{d+1 ...
Qingyue Zhang
doaj   +2 more sources

Koopman Invariant Subspaces and Finite Linear Representations of Nonlinear Dynamical Systems for Control. [PDF]

PLoS One, 2016
In this work, we explore finite-dimensional linear representations of nonlinear dynamical systems by restricting the Koopman operator to an invariant subspace spanned by specially chosen observable functions.
Brunton SL, Brunton BW, Proctor JL, Kutz JN.   +3 more
europepmc   +3 more sources

INVARIANT SUBSPACES IN UNBOUNDED DOMAINS

Проблемы анализа, 2021
We study subspaces of functions analytic in an unbounded convex domain of the complex plane and invariant with respect to the differentiation operator.
A. S. Krivosheev, O. A. Krivosheeva
doaj   +2 more sources

Probabilistic Perturbation Bounds for Invariant, Deflating and Singular Subspaces

Axioms
In this paper, we derive new probabilistic bounds on the sensitivity of invariant subspaces, deflation subspaces and singular subspaces of matrices. The analysis exploits a unified method for deriving asymptotic perturbation bounds of the subspaces under
P Hr Petkov
exaly   +3 more sources

Nonuniform sampling in principal shift-invariant subspaces of mixed Lebesgue spaces Lp,q(Rd+1)

Journal of Mathematical Analysis and Applications, 2017
Rui Li, Bei Liu
exaly   +2 more sources

Sparsity-promoting algorithms for the discovery of informative Koopman-invariant subspaces [PDF]

Journal of Fluid Mechanics, 2020
Koopman decomposition is a nonlinear generalization of eigen-decomposition, and is being increasingly utilized in the analysis of spatio-temporal dynamics. Well-known techniques such as the dynamic mode decomposition (DMD) and its linear variants provide
Shaowu Pan, Nicholas Arnold-Medabalimi, K. Duraisamy   +2 more
semanticscholar   +1 more source

Almost Invariant Subspaces of the Shift Operator on Vector-Valued Hardy Spaces [PDF]

Integral equations and operator theory, 2020
In this article, we characterize nearly invariant subspaces of finite defect for the backward shift operator acting on the vector-valued Hardy space which is a vectorial generalization of a result of Chalendar–Gallardo–Partington.
A. Chattopadhyay, Soma Das, Chandan Pradhan   +2 more
semanticscholar   +1 more source

Compressed Sampling in Shift-Invariant Spaces Associated With FrFT

IEEE Access, 2021
Shift-invariant and sampling spaces play a vital role in the fields of signal processing and image processing. In this paper, we extend the generalized shift-invariant and sampling subspaces from the traditional sampling spaces to the compressed sampling,
Haoran Zhao, Lei Zhang, Liyan Qiao
doaj   +1 more source

On a Perturbation Bound for Invariant Subspaces of Matrices

SIAM Journal on Matrix Analysis and Applications, 2014
Daniel Kressner
exaly   +2 more sources