Remarks on HNN extensions in operator algebras
نویسندگان
چکیده
منابع مشابه
Hnn Extensions of Von Neumann Algebras
Reduced HNN extensions of von Neumann algebras (as well as C-algebras) will be introduced, and their modular theory, factoriality and ultraproducts will be discussed. In several concrete settings, it will be illustrated how our results can be applied.
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By improving the previous construction in [18] we observe that any reduced HNN extension is a corner of a certain reduced amalgamated free product in both the von Neumann algebra and the C∗-algebra settings. Then, the same fact is shown for universal HNN extensions of C∗-algebras. We apply the observation to the questions of factoriality and type classification of HNN extensions of von Neumann ...
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This note includes supporting material for Guilbault’s one-hour talk summarized elsewhere in these proceedings. We supply the group theory necessary to argue that Guilbault’s tame ends cannot be pseudocollared. In particular, we show that certain groups (the interated Baumslag-Solitar groups) cannot have any non-trivial perfect subgroups. The absence of non-trivial perfect subgroups, in turn, e...
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ژورنال
عنوان ژورنال: Illinois Journal of Mathematics
سال: 2008
ISSN: 0019-2082
DOI: 10.1215/ijm/1254143997