Searcharxiv⌕ Search

arXiv · math/9803044

Exotic subfactors of finite depth with Jones indices (5+sqrt{13})/2 and (5+sqrt{17})/2

Abstract

We prove existence of subfactors of finite depth of the hyperfinite II_1 factor with indices (5+sqrt{13})/2= 4.302... and (5+sqrt{17})/2=4.561.... The existence of the former was announced by the second named author in 1993 and that of the latter has been conjectured since then. These are the only known subfactors with finite depth which do not arise from classical groups, quantum groups or rational conformal field theory.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

M. Asaeda, U. Haagerup. 1999-06-17. Exotic subfactors of finite depth with Jones indices (5+sqrt{13})/2 and (5+sqrt{17})/2. https://doi.org/10.1007/s002200050574

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Selfless Reduced Crossed Product $C^{*}$-Algebras Arising from Almost Periodic Actions

We prove that the reduced crossed product arising from an almost periodic action of an infinite countable discrete group on a unital, separable $C^*$-algebra is selfless whenever the crossed product is simple and monotracial and the group admits a topologically free extreme boundary action. We also give an alternative proof of a special case of a result of Gao, Junge, Kunnawalkam Elayavalli, Patchell, and Robert: the direct product of an exact $C^*$-simple group and a $C^*$-selfless group is $C^*$-selfless.

math.OA↗

Isomorphisms and representations of noncommutative function algebras

Let $V$ be a noncommutative (NC) variety in a NC operator ball. We study the dual operator algebra $H^\infty(V)$ of bounded NC functions on $V$, and the operator algebra $A(V)$ obtained as the closure of NC polynomials in $H^\infty(V)$. We identify the space of weak-$*$ continuous finite-dimensional representations of $H^\infty(V)$ as the similarity envelope $\widetilde{V}$ of $V$, and equip $\widetilde{V}$ with a metric which turns $\widetilde{V}$ into a complete invariant for $H^\infty(V)$, in the sense that $H^\infty(V)$ is weak-$*$ continuously isomorphic to $H^\infty(W)$ if and only if $\widetilde{V}$ and $\widetilde{W}$ are NC biholomorphic via a bi-Lipschitz map. Similar results are obtained in the completely bounded category as well as for the algebras $A(V)$ when $V$ is assumed homogeneous. In the case of homogeneous varieties $V$ and $W$, we obtain a sharper classification result, by which $H^\infty(V)$ is (completely) boundedly isomorphic to $H^\infty(W)$ if and only if there is a linear map which gives a bi-Lipschitz bijection between $\widetilde{W}$ and $\widetilde{V}$. The reduction to the linear case in the generality we work in depends on showing that the existence of maps implies the existence of origin-fixing maps, which we show using a novel ``two-circle trick" of independent interest. In the important case where the varieties are the full NC operator balls we find a striking rigidity phenomenon: if $A(B_E)$ and $A(B_F)$ are completely boundedly isomorphic then $E$ and $F$ are completely isometric. We also present a variety of examples illustrating the results and their sharpness, showing how several results from the literature fail to generalize to the setting studied here.

math.OA↗

Pointwise convergence of noncommutative discrete spherical ergodic averages

In this paper, we establish spherical maximal inequalities associated with commuting trace-preserving automorphisms on von Neumann algebras, extending Magyar-Stein-Wainger's discrete spherical maximal inequalities to the noncommutative setting. On a noncommutative probability space, we further prove that, under a strong ergodicity assumption, the corresponding discrete spherical averages converge bilaterally almost uniformly to $τ(x)1$ for every $x\in L_p(\mathcal M)$, $\frac{d}{d-2}<p\leq\infty$, when $d\geq5$.

math.OA↗