Results 71 to 80 of about 15,235 (310)

On the reflexivity of algebras and linear spaces of operators.

Michigan Mathematical Journal, 1986
Let A be a weakly closed algebra of operators on Hilbert space H. Assume that for all weakly continuous functionals \(\{\phi_{ij}:\) \(1\leq i\leq 2\), \(1\leq j\leq 3\}\) on A there exist \(x_ 1,x_ 2,y_ 1,y_ 2,y_ 3\in H\) such that \(\phi_{ij}(T)=(Tx_ i,y_ j)\), \(1\leq i\leq 2\), \(i\leq j\leq 3\), \(T\in A\).
Bercovici, H., Foias, C., Pearcy, C.
openaire   +3 more sources

Design and analysis strategies for robust microbiome ageing research

FEBS Letters, EarlyView.
The gut microbiome changes with age and associates with age‐related morbidity and mortality, establishing it as a potential biomarker and intervention target for ageing. Realising this potential requires methodological rigour, yet distinguishing biological signals from methodological artefacts remains challenging across cohorts. This review provides an
Mark Olenik, İsmail Güderer, Yi Wang, Tayyaba Alvi, Prasoon Pandey, Handan Melike Dönertaş   +5 more
wiley   +1 more source

Some Inequalities for (α,β)-Normal Operators in Hilbert Spaces [PDF]

, 2007
An operator T is called (α,β)-normal (0 ≤ α ≤ 1 ≤ β) if α²T*T ≤ TT* ≤ β²T*T. In this paper, we establish various inequalities between the operator norm and its numerical radius of (α,β)-normal operators in Hilbert spaces.
Dragomir, Sever S, Moslehian, Mohammad Sal   +1 more
core  

Cebyšev’s type inequalities for positive linear maps of selfadjoint operators in Hilbert spaces [PDF]

Mathematica Moravica, 2017
Some inequalities for positive linear maps of continuous synchronous (asynchronous) functions of selfadjoint linear operators in Hilbert spaces, under suitable assumptions for the involved operators, are given.
Sever Silvestru Dragomir
doaj  

Reconstructing enzyme evolution by protein engineering

FEBS Letters, EarlyView.
Natural enzyme evolution can be retraced by protein engineering methods such as directed evolution, rational design, and ancestral sequence reconstruction. These approaches reveal how enzymes emerged from ligand‐binding scaffolds, developed varying substrate preferences, formed oligomeric complexes, adapted to environmental changes, and evolved novel ...
Lukas Drexler, Markus R. Busch, Reinhard Sterner   +2 more
wiley   +1 more source

Hypercyclic tuples of operators on $C^n$ and $R^n$ [PDF]

, 2012
A tuple $(T_1,\dots,T_n)$ of continuous linear operators on a topological vector space $X$ is called hypercyclic if there is $x\in X$ such that the the orbit of $x$ under the action of the semigroup generated by $T_1,\dots,T_n$ is dense in $X$.
Shkarin, Stanislav
core  

Some Fixed Point Theorems in Fuzzy n-Normed Spaces [PDF]

, 2010
The main purpose of this paper is to study the existence of a fixed points in fuzzy n-normed spaces. we proved our main results, a fixed point theorem for a self mapping and a common fixed point theorem for a pair of weakly compatible mappings on fuzzy n-
Rahmat, Mohamad Rafi Segi, Elagan, Sayed Khalil   +1 more
core   +1 more source

Mixed C-Cosine of Continuous Linear Operators on Complex p-Banach Spaces

Pan-American Journal of Mathematics
In the present work, we define and examine the mixed C-cosine families of continuous linear operators on complex p-Banach spaces where 0 p 1. Finally, we will demonstrate several results on the mixed C-cosine families of continuous linear operators on ...
Jawad Ettayb
doaj   +1 more source

A Dichotomy for Linear Spaces of Toeplitz Operators

Journal of Functional Analysis, 1998
For a Hilbert space \(H\), \(B(H)\) denotes the algebra of all bounded linear operators on \(H\); and the reflexive closure of a subspace \(S\) in \(B(H)\) is defined by: \[ \text{ref}(S)= \{T\in B(H); T(f)\in\overline{S(f)}, \forall f\in H\}. \] \(S\) is said to be reflexive if \(\text{ref}(S)= S\), and transitive if \(\text{ref}(S)= B(H)\).
Azoff, Edward A, Ptak, Marek
openaire   +2 more sources

Tumour–host interactions in Drosophila: mechanisms in the tumour micro‐ and macroenvironment

Molecular Oncology, EarlyView.
This review examines how tumour–host crosstalk takes place at multiple levels of biological organisation, from local cell competition and immune crosstalk to organism‐wide metabolic and physiological collapse. Here, we integrate findings from Drosophila melanogaster studies that reveal conserved mechanisms through which tumours hijack host systems to ...
José Teles‐Reis, Tor Erik Rusten
wiley   +1 more source