776 research outputs found
On twisted group C-algebras associated with FC-hypercentral groups and other related groups
We show that the twisted group C-algebra associated with a discrete
FC-hypercentral group is simple (resp. has a unique tracial state) if and only
if Kleppner's condition is satisfied. This generalizes a result of J. Packer
for countable nilpotent groups. We also consider a larger class of groups, for
which we can show that the corresponding reduced twisted group C-algebras
have a unique tracial state if and only if Kleppner's condition holds.Comment: 16 pages. Some minor changes, mostly in subsection 2.3; two
references adde
On discrete twisted C*-dynamical systems, Hilbert C*-modules and regularity
We first give an overview of the basic theory for discrete unital twisted
C*-dynamical systems and their covariant representations on Hilbert C*-modules.
After introducing the notion of equivariant representations of such systems and
their product with covariant representations, we prove a kind of Fell
absorption principle saying that the product of an induced regular equivariant
representation with a covariant faithful representation is weakly equivalent to
an induced regular covariant representation. This principle is the key to our
main result, namely that a certain property, formally weaker than Exel's
approximation property, ensures that the system is regular, i.e., the
associated full and reduced C*-crossed products are canonically isomorphic.Comment: Final version, to appear in Muenster J. Math. A permanence result for
the weak approximation property, some corollaries of it and two examples have
been added to Section 5. Some side results in Section 4 have been removed and
will be included in a subsequent paper. The Introduction has also been partly
rewritte
On amenability and co-amenability of algebraic quantum groups and their corepresentations
We introduce and study several amenability properties for unitary
corepresentations and *-representations of algebraic quantum groups, which may
be used to characterize amenability or co-amenability of such groups. As a
background for this study, we also investigate the involved tensor
C*-categories.Comment: 46 pages, (some misprints corrected, a couple of remarks and a new
reference added
Amenability and co-amenability of algebraic quantum groups
We define concepts of amenability and co-amenability for algebraic quantum
groups in the sense of A. Van Daele. We show that co-amenability of an
algebraic quantum group always implies amenability of its dual. Various
necessary and/or sufficient conditions for amenability or co-amenability are
obtained. Co-amenability is shown to have interesting consequences for the
modular theory in the case that the algebraic quantum group is of compact type.Comment: 25 pages, with some minor corrections, as to appear in the IJMM
Co-Amenability of compact quantum groups
We study the concept of co-amenability for a compact quantum group. Several
conditions are derived that are shown to be equivalent to it. Some consequences
of co-amenability that we obtain are faithfulness of the Haar integral and
automatic norm-boundedness of positive linear functionals on the quantum
group's Hopf *-algebra (neither of these properties necessarily holds without
co-amenability).Comment: 25 pages. LaTe
The significance of pre-iridal monocellular membranes in dogs and those with anterior segment dysgenesis associated glaucoma, secondary glaucoma, and primary glaucoma
The abstract of this item is unavailable due to an embargo
TMG 4 (2018): Seals--Making and Marking Connections Across the Medieval World
Extensive geographic coverage, including China, South East Asia, Arabia, Sasanian Persia, the Muslim Empire, the Byzantine empire, and Western Europe allows the essays gathered in this volume to offer a well differentiated examination of seals and sealing practices between 400 and 1500 CE. Contributors expose rather than assume the inter-subjective, transnational, and transcultural connectivity at work within the varied processes mediated by seals and sealing – representation, authorization, identification, and transmission. These essays encourage an understanding that seals operated in liminal, transitional situations arising from legal, administrative, martial, mercantile, or diplomatic encounters, creating cross-cultural sealing networks in which adaption and accommodation underlay the force of seals as objects and images that generate sociocultural identification through mutual exchange and visual hybridity.https://scholarworks.wmich.edu/medieval_globe/1003/thumbnail.jp
Description of two new species of the genus Micranurida Börner, 1901 (Collembola: Neanuridae, Pseudachorutinae) from Russia, with notes on the genus Lanzhotia Rusek, 1985
Micranurida rassica sp. n. and Micranarida potapovi sp. n. from the Russian Far East are fully illustrated and described. Both new species belong to a small group of Micranurida species characterized by thick globular sensilla on thorax II and abdomen IV. Remarks on Lanzhotia braclzycera Rusek, 1985 are also included
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