Eta-series and a Boolean Bercovici-Pata bijection for bounded k-tuples

dc.creatorBelinschi, Serban T.
dc.creatorNica, Alexandru
dc.date2006-08-25
dc.date2007-06-25
dc.date.accessioned2026-07-07T08:12:00Z
dc.date.available2026-07-07T08:12:00Z
dc.descriptionOn the space of (non-commutative) distributions of k-tuples of selfadjoint elements in a $C^*$-probability space $D_c(k)$, one has an operation $\freeplus$ of free additive convolution, and one can consider the subspace $D_c^{inf-div}$ of distributions which are infinitely divisible with respect to this operation. The linearizing transform for free additive convolution is the R-transform. Thus, one has $R_{μ\freeplusν}=R_μ+R_ν$. The eta-series $η_μ$ is the counterpart of $R_μ$ in the theory of Boolean convolution. We prove that the space of eta-series of distributions belonging to $D_c(k)$ coincides with the space of R-transforms of distributions which are infinitely divisible with respect to free additive convolution. As a consequence of this fact, one can define a bijection $B : D_c(k) \to D_c^{inf-div}$ via the formula $R_{B(μ)} = η_μ$, for all distributions $μ$ in $D_c(k)$. We show that $B$ is a multi-variable analogue of a bijection studied by Bercovici and Pata for k=1, and we prove a theorem about convergence in moments which parallels the Bercovici-Pata result. On the other hand we prove the formula $B(μ\freetimesν) = B(μ) \freetimes B(ν),$ with $μ,ν$ considered in a space $D^{alg}(k)$ containing $D_c (k)$ where the operation of free multiplicative convolution $\freetimes$ always makes sense. An equivalent reformulation for this equality is that $η_{μ\freetimesν}=η_μ \freestar η_ν,$ for all $μ,ν\in D^{alg}(k)$. This shows that, in a certain sense, eta-series behave in the same way as R-transforms in connection to the operation of multiplication of free k-tuples of non-commutative random variables.
dc.descriptionLaTeX, 41 pages. Minor changes and corrections, added references
dc.identifierhttps://arxiv.org/abs/math/0608622
dc.identifierhttp://arxiv.org/abs/math/0608622
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/132305
dc.subjectOperator Algebras
dc.subjectCombinatorics
dc.subject46L54
dc.titleEta-series and a Boolean Bercovici-Pata bijection for bounded k-tuples
dc.typetext

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