New classes of analytic and Gevrey semigroups and applications

Angelo Favini; Roberto Triggiani

Displaying similar documents to “New classes of analytic and Gevrey semigroups and applications”

Square functions, bounded analytic semigroups, and applications

Christian Le Merdy (2007)

Banach Center Publications

Similarity:

To any bounded analytic semigroup on Hilbert space or on $L^{p}$ -space, one may associate natural ’square functions’. In this survey paper, we review old and recent results on these square functions, as well as some extensions to various classes of Banach spaces, including noncommutative $L^{p}$ -spaces, Banach lattices, and their subspaces. We give some applications to $H^{\infty}$ functional calculus, similarity problems, multiplier theory, and control theory.

On a probabilistic problem on finite semigroups

Attila Nagy, Csaba Tóth (2023)

Commentationes Mathematicae Universitatis Carolinae

Similarity:

We deal with the following problem: how does the structure of a finite semigroup $S$ depend on the probability that two elements selected at random from $S$ , with replacement, define the same inner right translation of $S$ . We solve a subcase of this problem. As the main result of the paper, we show how to construct not necessarily finite medial semigroups in which the index of the kernel of the right regular representation equals two.

On the theory of remediability

Hassan Emamirad (2003)

Banach Center Publications

Similarity:

Suppose ${G ₁ (t)}_{t \geq 0}$ and ${G ₂ (t)}_{t \geq 0}$ are two families of semigroups on a Banach space X (not necessarily of class C₀) such that for some initial datum u₀, G₁(t)u₀ tends towards an undesirable state u*. After remedying by means of an operator ρ we continue the evolution of the state by applying G₂(t) and after time 2t we retrieve a prosperous state u given by u = G₂(t)ρG₁(t)u₀. Here we are concerned with various properties of the semigroup (t): ρ → G₂(t)ρG₁(t). We define (X) to be the space of remedial operators...

Analytic semigroups on vector valued noncommutative $L^{p}$ -spaces

Cédric Arhancet (2013)

Studia Mathematica

Similarity:

We give sufficient conditions on an operator space E and on a semigroup of operators on a von Neumann algebra M to obtain a bounded analytic or R-analytic semigroup ( ${(T \otimes I d_{E})}_{t \geq 0}$ on the vector valued noncommutative $L^{p}$ -space $L^{p} (M, E)$ . Moreover, we give applications to the $H^{\infty} (Σ_{θ})$ functional calculus of the generators of these semigroups, generalizing some earlier work of M. Junge, C. Le Merdy and Q. Xu.

A $C^{*}$ -algebraic Schoenberg theorem

Ola Bratteli, Palle E. T. Jorgensen, Akitaka Kishimoto, Donald W. Robinson (1984)

Annales de l'institut Fourier

Similarity:

Let $𝔄$ be a $C^{*}$ -algebra, $G$ a compact abelian group, $τ$ an action of $G$ by $*$ -automorphisms of $𝔄, 𝔄^{τ}$ the fixed point algebra of $τ$ and $𝔄_{F}$ the dense sub-algebra of $G$ -finite elements in $𝔄$ . Further let $H$ be a linear operator from $𝔄_{F}$ into $𝔄$ which commutes with $τ$ and vanishes on $𝔄^{τ}$ . We prove that $H$ is a complete dissipation if and only if $H$ is closable and its closure generates a $C_{0}$ -semigroup of completely positive contractions. These complete dissipations are classified in terms of certain twisted negative...

Inverses of generators of nonanalytic semigroups

Ralph deLaubenfels (2009)

Studia Mathematica

Similarity:

Suppose A is an injective linear operator on a Banach space that generates a uniformly bounded strongly continuous semigroup ${e^{t A}}_{t \geq 0}$ . It is shown that $A^{- 1}$ generates an $O (1 + τ) A {(1 - A)}^{- 1}$ -regularized semigroup. Several equivalences for $A^{- 1}$ generating a strongly continuous semigroup are given. These are used to generate sufficient conditions on the growth of ${e^{t A}}_{t \geq 0}$ , on subspaces, for $A^{- 1}$ generating a strongly continuous semigroup, and to show that the inverse of -d/dx on the closure of its image in L¹([0,∞)) does not generate...

Operator theoretic properties of semigroups in terms of their generators

S. Blunck, L. Weis (2001)

Studia Mathematica

Similarity:

Let $(T_{t})$ be a C₀ semigroup with generator A on a Banach space X and let be an operator ideal, e.g. the class of compact, Hilbert-Schmidt or trace class operators. We show that the resolvent R(λ,A) of A belongs to if and only if the integrated semigroup $S_{t} : = \int_{0}^{t} T_{s} d s$ belongs to . For analytic semigroups, $S_{t} \in$ implies $T_{t} \in$ , and in this case we give precise estimates for the growth of the -norm of $T_{t}$ (e.g. the trace of $T_{t}$ ) in terms of the resolvent growth and the imbedding D(A) ↪ X.

Analytic semigroups generated on a functional extrapolation space by variational elliptic equations

Vincenzo Vespri (1988)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

Similarity:

We prove that any elliptic operator of second order in variational form is the infinitesimal generator of an analytic semigroup in the functional space $C^{-1,\alpha}(\Omega)$ consinsting of all derivatives of hölder-continuous functions in $\Omega$ where $\Omega$ is a domain in $\mathbb{R}^{n}$ not necessarily bounded. We characterize, moreover the domain of the operator and the interpolation spaces between this and the space $C^{-1,\alpha}(\Omega)$ . We prove also that the spaces $C^{-1,\alpha}(\Omega)$ can be considered as extrapolation spaces relative to suitable non-variational...

Generation of analytic semigroups by elliptic operators of second order in Hölder spaces

Sergio Campanato (1980)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti

Similarity:

Nella presente nota si comunica il seguente risultato: Un operatore ellittico del secondo ordine, con condizione di Dirichlet al bordo, è generatore infinitesimale di un semigruppo analitico in $t$ con la topologia degli spazi Hölderiani. La dimostrazione sarà esposta nel lavoro [2].

On semigroups of $σ$ -endomorphisms

Iwanik, Anzelm

Similarity:

Good and very good magnifiers

Marin Gutan (2000)

Bollettino dell'Unione Matematica Italiana

Similarity:

Un elemento $a$ di un semigruppo $S$ è un elemento accrescitivo sinistro se la traslazione $λ_{a}$ di $S$ , associata all'elemento $a$ , è surgettiva e non è iniettiva (E. S. Ljapin, [13], § 5). Così, per ogni elemento accrescitivo sinistro $a$ , esiste un sottoinsieme proprio $M$ di $S$ tale che la restrizione a $M$ di $λ_{a}$ è biunivoca. Se $M$ è un sottosemigruppo (risp. un ideale destro) di $S$ , l'elemento accrescitivo sinistro $a$ viene detto buono (risp. molto buono) (F. Migliorini [15], [16], [17]). Utilizzando...

Compactness properties of Feller semigroups

G. Metafune, D. Pallara, M. Wacker (2002)

Studia Mathematica

Similarity:

We study the compactness of Feller semigroups generated by second order elliptic partial differential operators with unbounded coefficients in spaces of continuous functions in $ℝ^{N}$ .