English
Related papers

Related papers: On Compactifications of bounded $C_0-$semigroups

200 papers

Let P be a semigroup that admits an embedding into a group G. Assume that the embedding satisfies a certain Toeplitz condition and that the Baum-Connes conjecture holds for G. We prove a formula describing the K- theory of the reduced…

Operator Algebras · Mathematics 2012-05-25 Joachim Cuntz , Siegfried Echterhoff , Xin Li

We study two classes of operator algebras associated with a unital subsemigroup $P$ of a discrete group $G$: one related to universal structures, and one related to co-universal structures. First we provide connections between universal…

Operator Algebras · Mathematics 2022-03-09 Evgenios T. A. Kakariadis , Elias G. Katsoulis , Marcelo Laca , Xin Li

We study `constrained generalized Killing (s)pinors', which characterize supersymmetric flux compactifications of supergravity theories. Using geometric algebra techniques, we give conceptually clear and computationally effective methods…

High Energy Physics - Theory · Physics 2016-11-08 Calin-Iuliu Lazaroiu , Elena-Mirela Babalic , Ioana-Alexandra Coman

This paper constructs a foundation to analyze semi-group actions, group actions, filtrations, and decompositions in a unified manner. In fact, though the studies of decomposition can be applied to foliated spaces and group actions, they can…

Dynamical Systems · Mathematics 2023-08-16 Tomoo Yokoyama

We introduce a class of locally compact Hausdorff groupoids and show how to associate C*-algebras to them in a way which generalizes the reduced C*-algebra of an 'etale groupoid. Focusing on criteria for simplicity and existence of Cartan…

Operator Algebras · Mathematics 2009-08-29 Klaus Thomsen

In this paper we consider A-Fredholm and semi-A-Fredholm operators on Hilbert C*-modules over a W*-algebra A defined in [3],[10]. Using the assumption that A is a W*-algebra (and not an arbitrary C*-algebra), we obtain several results such…

Operator Algebras · Mathematics 2020-02-18 Stefan Ivkovic

In this paper we obtain some noncommutative multiplier theorems and maximal inequalities on semigroups. As applications, we obtain the corresponding individual ergodic theorems. Our main results extend some classical results of Stein and…

Functional Analysis · Mathematics 2017-03-01 Yong Jiao , Maofa Wang

We give a new and very short proof of a theorem of Greiner asserting that a positive and contractive $C_0$-semigroup on an $L^p$-space is strongly convergent in case that it has a strictly positive fixed point and contains an integral…

Functional Analysis · Mathematics 2017-06-06 Moritz Gerlach , Jochen Glück

This paper reviews results and techniques from the authors' previous work "Symplectomorphism group relations and degenerations of Landau-Ginzburg models" and applies them in basic examples. The main example is the $A_n$ category where we…

Algebraic Geometry · Mathematics 2015-06-05 Colin Diemer , Ludmil Katzarkov , Gabriel Kerr

Given a split semisimple group over a local field, we consider the maximal Satake-Berkovich compactification of the corresponding Euclidean building. We prove that it can be equivariantly identified with the compactification which we get by…

Group Theory · Mathematics 2023-06-22 Bertrand Remy , Amaury Thuillier , Annette Werner

Let Z be an algebraic homogeneous space Z=G/H attached to real reductive Lie group G. We assume that Z is real spherical, i.e., minimal parabolic subgroups have open orbits on Z. For such spaces we investigate their large scale geometry and…

Representation Theory · Mathematics 2022-10-17 Friedrich Knop , Bernhard Krötz , Eitan Sayag , Henrik Schlichtkrull

We prove that the semigroup operation of a topological semigroup $S$ extends to a continuous semigroup operation on its the Stone-\v{C}ech compactification $\beta S$ provided $S$ is a pseudocompact openly factorizable space, which means…

General Topology · Mathematics 2011-10-11 Taras Banakh , Svetlana Dimitrova

In this paper, we consider the diagonal action of a connected semisimple group of adjoint type on its wonderful compactification. We show that the semi-stable locus is a union of the $G$-stable pieces and we calculate the geometric…

Algebraic Geometry · Mathematics 2009-07-03 Xuhua He , Jason Starr

A generalized topology in a set $X$ is a collection $\text{Cov}_X$ of families of subsets of $X$ such that the triple $(X,\bigcup \text{Cov}_X,\text{Cov}_X)$ is a generalized topological space in the sense of Delfs and Knebusch. In this…

General Topology · Mathematics 2020-09-09 Artur Piȩkosz , Eliza Wajch

In our previous paper "Bruhat-Tits theory from Berkovich's point of view. I ? Realizations and compactifications of buildings", we investigated realizations of the Bruhat-Tits building B(G,k) of a connected and reductive linear algebraic…

Group Theory · Mathematics 2012-10-04 Bertrand Remy , Amaury Thuillier , Annette Werner

We prove collective versions of semi-duality theorems for sets of almost (limitedly, order) L-weakly compact operators.

Functional Analysis · Mathematics 2024-10-29 Safak Alpay , Eduard Emelyanov , Svetlana Gorokhova

A semiregular operator on a Hilbert C^*-module, or equivalently, on the C^*-algebra of `compact' operators on it, is a closable densely defined operator whose adjoint is also densely defined. It is shown that for operators on extensions of…

Operator Algebras · Mathematics 2016-09-07 Arupkumar Pal

This paper continues the same-named article, Part I (math.QA/9812083). We give a global operator approach to the WZWN theory for compact Riemann surfaces of an arbitrary genus g with marked points. Globality means here that we use…

Algebraic Geometry · Mathematics 2007-05-23 Martin Schlichenmaier , Oleg K. Sheinman

We study the weak limit semigroup of an operator $T$, i.e., the set of all operators being weak limit points of the powers of $T$, in three different but related contexts: Koopman operators of measure-preserving transformations,…

Functional Analysis · Mathematics 2026-04-14 Tanja Eisner , Valentin Gillet

We introduce an axiomatization of the notion of a semidirect product of locally compact quantum groups and study properties. Our approach is slightly different from the one introduced in the thesis of S.~Roy and, unlike the investigations…

Operator Algebras · Mathematics 2014-10-17 Paweł Kasprzak , Piotr M. Sołtan
‹ Prev 1 4 5 6 7 8 10 Next ›