Results 61 to 70 of about 1,093 (132)

On locally finite groups whose derived subgroup is locally nilpotent

Mathematische Nachrichten, Volume 297, Issue 12, Page 4389-4400, December 2024.
Abstract A celebrated theorem of Helmut Wielandt shows that the nilpotent residual of the subgroup generated by two subnormal subgroups of a finite group is the subgroup generated by the nilpotent residuals of the subgroups. This result has been extended to saturated formations in Ballester‐Bolinches, Ezquerro, and Pedreza‐Aguilera [Math. Nachr.
Marco Trombetti
wiley   +1 more source

On the Weakly Hypercyclic Composition Operators on Hardy Spaces

Journal of Mathematical Extension, 2010
An operator T on a Banach space X is said to be weakly hypercyclic if there exists a vector x ∈ X whose orbit under T is weakly dense in X. We show that every weakly hypercyclic composition operator on classic Hardy space H2 is norm hypercyclic.
H. Rezaei
doaj  

Operators with hypercyclic Cesaro means [PDF]

Studia Mathematica, 2002
Let \(T\) be a bounded linear operator on complex Banach space \(B\) and consider the arithmetic means \(M_n(T)= (I+ T+\cdots+ T^{n-1})/n\). The operator \(T\) is said to be hypercyclic if there exists a vector \(x\) in \(B\) such that the orbit \(\{T^n x\}\) is dense in \(B\).
openaire   +1 more source

Topologically mixing hypercyclic operators [PDF]

Proceedings of the American Mathematical Society, 2003
Let X X be a separable Fréchet space. We prove that a linear operator T : X → X T:X\to X satisfying a special case of the Hypercyclicity Criterion is topologically mixing, i.e.
Costakis, George, Sambarino, Martín
openaire   +1 more source

Note on epsilon-cyclic operator

Ibn Al-Haitham Journal for Pure and Applied Sciences
In this paper, we investigated the concept of ε-diskcyclic operators on a separable infinite-dimensional Hilbert space . A bounded linear operator  is called -diskcyclic if there exists a vector in  such that its disk orbit  visits every cone of ...
Muammer Badree Abed, Zeana Zaki Jamil
doaj   +1 more source

Multiplicative structures of hypercyclic functions for convolution operators

, 2017
In this note, it is proved the existence of an infinitely generated multiplicative group consisting of entire functions that are, except for the constant function 1, hypercyclic with respect to the convolution operator associated to a given entire ...
Bernal-González, Luis, Conejero, J. Alberto, Costakis, George, Seoane-Sepúlveda, Juan B.   +3 more
core   +1 more source

Sums of hypercyclic operators

Journal of Functional Analysis, 2003
A (bounded) operator \(T\) on a complex infinite-dimensional separable Banach space \(X\) is said to be hypercyclic if there is a (hypercyclic) vector \(x \in X\) such that its orbit \(O(T,x):=\{x,Tx,T^2x,\dots\}\) is dense in \(X\). The operator \(T\) is called chaotic if it is hypercyclic and the set of periodic points of \(T\) is dense in \(X ...
openaire   +2 more sources

Hypercyclic operators failing the Hypercyclicity Criterion on classical Banach spaces

Journal of Functional Analysis, 2007
Let \(X\) be a topological vector space over \(\mathbb{R}\) or \(\mathbb{C}\). A (continuous, linear) operator \(T:X \to X\) is said to be hypercyclic if there exists some \(x \in X\) whose \(T\)-orbit \(\{T^n x: n\in{\mathbb{N}}\}\) is dense in \(X\). In [J.~Funct.~Anal.\ 99, 179--190 (1991; Zbl 0758.47016)], \textit{D.\,Herrero} posed the problem of ...
Bayart, Frédéric, Matheron, Etienne
openaire   +2 more sources

Existence and nonexistence of hypercyclic semigroups [PDF]

, 2007
In these notes we provide a new proof of the existence of a hypercyclic uniformly continuous semigroup of operators on any separable infinitedimensional Banach space that is very different from –and considerably shorter than– the one recently given by ...
Bernal González, Luis, Grosse-Erdmann, Karl-Goswin   +1 more
core  

Hypercyclic differentiation operators

, 1999
8 ...
Aron, Richard M., Bes, Juan P.
openaire   +2 more sources