Results 11 to 20 of about 443 (51)

The transfer ideal under the action of orthogonal group in modular case

open access: yesOpen Mathematics, 2022
In this paper, we study the structures of the invariant subspaces under the action of orthogonal group O2ν(Fq,S){O}_{2\nu }\left({F}_{q},S). In particular, we give a detailed description of 2-codimensional invariant subspaces.
Lingli Zeng
doaj   +1 more source

Linear isomorphic spaces of fractional-order difference operators

open access: yesAlexandria Engineering Journal, 2021
In the present paper, we intend to make an approach to introduce and study the applications of fractional-order difference operators by generating Orlicz almost null and almost convergent sequence spaces.
S.A. Mohiuddine   +3 more
doaj   +1 more source

The invariant subspaces of S ⊕ S*

open access: yesConcrete 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.
Timotin Dan
doaj   +1 more source

On some nonlinear parabolic equations with variable exponents and measure data

open access: yesMoroccan Journal of Pure and Applied Analysis, 2020
We prove the existence of renormalized solutions to a class of nonlinear evolution equations, supplemented with initial and Dirichlet condition in the framework of generalized Sobolev spaces. The data are assumed merely integrable.
Hamdaoui Bouchra El, Bennouna Jaouad
doaj   +1 more source

Proper contractions and invariant subspaces

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 28, Issue 4, Page 223-230, 2001., 2001
Let T be a contraction and A the strong limit of {T∗nTn}n ≥ 1. We prove the following theorem: if a hyponormal contraction T does not have a nontrivial invariant subspace, then T is either a proper contraction of class 𝒞00 or a nonstrict proper contraction of class 𝒞10 for which A is a completely nonprojective nonstrict proper contraction.
C. S. Kubrusly, N. Levan
wiley   +1 more source

Some remarks on the invariant subspace problem for hyponormal operators

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 28, Issue 6, Page 359-365, 2001., 2001
We make some remarks concerning the invariant subspace problem for hyponormal operators. In particular, we bring together various hypotheses that must hold for a hyponormal operator without nontrivial invariant subspaces, and we discuss the existence of such operators.
Vasile Lauric
wiley   +1 more source

Somewhere Dense Orbit that is not Dense on a Complex Hilbert Space

open access: yesConcrete Operators, 2019
In this paper, we present the existence of n-tuple of operators on complex Hilbert space that has a somewhere dense orbit and is not dense. We give the solution to the question stated in [11]: “Is there n-tuple of operators on a complex Hilbert space ...
Wilberth Neema   +2 more
doaj   +1 more source

Hyperinvariant subspaces for some operators on locally convex spaces

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 23, Issue 12, Page 807-814, 2000., 2000
Some results concerning hyperinvariant subspaces of some operators on locally convex spaces are considered. Denseness of a class of operators which have a hyperinvariant subspace in the algebra of locally bounded operators is proved.
Edvard Kramar
wiley   +1 more source

Cohyponormal operators with the single valued extension property

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 9, Issue 4, Page 659-663, 1986., 1986
It is proved that in order to find a nontrivial hyperinvariant subspace for a cohyponormal operator it suffices to make the further assumption that the operator have the single‐valued extension property.
Ridgley Lange, Shengwang Wang
wiley   +1 more source

A few results on some nonlinear parabolic problems in Orlicz-Sobolev spaces

open access: yesMoroccan Journal of Pure and Applied Analysis, 2018
In this paper, we present our results (see our papers), which concern the existence of the renormalized solutions for equations of the type:
Redwane Hicham
doaj   +1 more source

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