ترغب بنشر مسار تعليمي؟ اضغط هنا

Hypergroups with Unique Alpha-Means

100   0   0.0 ( 0 )
 نشر من قبل Azita Mayeli
 تاريخ النشر 2008
  مجال البحث
والبحث باللغة English




اسأل ChatGPT حول البحث

Let $K$ be a commutative hypergroup and $alphain hat{K}$. We show that $K$ is $alpha$-amenable with the unique $alpha$-mean $m_alpha$ if and only if $m_alphain L^1(K)cap L^2(K)$ and $alpha$ is isolated in $hat{K}$. In contrast to the case of amenable noncompact locally compact groups, examples of polynomial hypergroups with unique $alpha$-means ($alpha ot=1$) are given. Further examples emphasize that the $alpha$-amenability of hypergroups depends heavily on the asymptotic behavior of Haar measures and characters.



قيم البحث

اقرأ أيضاً

118 - Ahmadreza Azimifard 2009
Let $K$ denote a locally compact commutative hypergroup, $L^1(K)$ the hypergroup algebra, and $alpha$ a real-valued hermitian character of $K$. We show that $K$ is $alpha$-amenable if and only if $L^1(K)$ is $alpha$-left amenable. We also consider the $alpha$-amenability of hypergroup joins and polynomial hypergroups in several variables as well as a single variable.
148 - Ahmadreza Azimifard 2008
Let $UC(K)$ denote the Banach space of all bounded uniformly continuous functions on a hypergroup $K$. The main results of this article concern on the $alpha$-amenability of $UC(K)$ and quotients and products of hypergroups. It is also shown that a S turm-Liouville hypergroup with a positive index is $alpha$-amenable if and only if $alpha=1$.
We prove that a uniform pro-p group with no nonabelian free subgroups has a normal series with torsion-free abelian factors. We discuss this in relation to unique product groups. We also consider generalizations of Hantzsche-Wendt groups.
We show that topological amenability of an action of a countable discrete group on a compact space is equivalent to the existence of an invariant mean for the action. We prove also that this is equivalent to vanishing of bounded cohomology for a clas s of Banach G-modules associated to the action, as well as to vanishing of a specific cohomology class. In the case when the compact space is a point our result reduces to a classic theorem of B.E. Johnson characterising amenability of groups. In the case when the compact space is the Stone-v{C}ech compactification of the group we obtain a cohomological characterisation of exactness for the group, answering a question of Higson.
71 - Jared T. White 2020
Let $G$ be an amenable group. We define and study an algebra $mathcal{A}_{sn}(G)$, which is related to invariant means on the subnormal subgroups of $G$. For a just infinite amenable group $G$, we show that $mathcal{A}_{sn}(G)$ is nilpotent if and on ly if $G$ is not a branch group, and in the case that it is nilpotent we determine the index of nilpotence. We next study $operatorname{rad} ell^1(G)^{**}$ for an amenable branch group $G$, and show that it always contains nilpotent left ideals of arbitrarily large index, as well as non-nilpotent elements. This provides infinitely many finitely-generated counterexamples to a question of Dales and Lau, first resolved by the author in a previous article, which asks whether we always have $(operatorname{rad} ell^1(G)^{**})^{Box 2} = { 0 }$. We further study this question by showing that $(operatorname{rad} ell^1(G)^{**})^{Box 2} = { 0 }$ imposes certain structural constraints on the group $G$.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا