Zobrazeno 1 - 10
of 53
pro vyhledávání: '"Musat, Magdalena"'
Publikováno v:
Annales Henri Poincar\'e, 22(10), 3455-3496 (2021)
We introduce and study two new classes of unital quantum channels. The first class describes a 2-parameter family of channels given by completely positive (CP) maps $M_3({\bf C}) \mapsto M_3({\bf C})$ which are both unital and trace-preserving. Almos
Externí odkaz:
http://arxiv.org/abs/2006.03414
Autor:
Musat, Magdalena, Rørdam, Mikael
We relate factorizable quantum channels on $M_n$, for $n \ge 2$, via their Choi matrix, to certain correlation matrices, which, in turn, are shown to be parametrized by traces on the unital free product $M_n * M_n$. Factorizable maps that admit a fin
Externí odkaz:
http://arxiv.org/abs/1903.10182
Autor:
Musat, Magdalena, Rørdam, Mikael
We show that there exist factorizable quantum channels in each dimension $\ge 11$ which do not admit a factorization through any finite dimensional von Neumann algebra, and do require ancillas of type II$_1$, thus witnessing new infinite-dimensional
Externí odkaz:
http://arxiv.org/abs/1806.10242
By analogy with the well-established notions of just-infinite groups and just-infinite (abstract) algebras, we initiate a systematic study of just-infinite C*-algebras, i.e., infinite dimensional C*-algebras for which all proper quotients are finite
Externí odkaz:
http://arxiv.org/abs/1604.08774
Autor:
Haagerup, Uffe, Musat, Magdalena
We establish a reformulation of the Connes embedding problem in terms of an asymptotic property of factorizable completely positive maps. We also prove that the Holevo-Werner channels W_n^- are factorizable, for all odd integers n different from 3. F
Externí odkaz:
http://arxiv.org/abs/1408.6476
Autor:
Haagerup, Uffe, Musat, Magdalena
We study factorization and dilation properties of Markov maps between von Neumann algebras equipped with normal faithful states, i.e., completely positive unital maps which preserve the given states and also intertwine their automorphism groups. The
Externí odkaz:
http://arxiv.org/abs/1009.0778
Autor:
Haagerup, Uffe, Musat, Magdalena
In 1991 Effros and Ruan conjectured that a certain Grothendieck-type inequality for a bilinear form on C$^*$-algebras holds if (and only if) the bilinear form is jointly completely bounded. In 2002 Pisier and Shlyakhtenko proved that this inequality
Externí odkaz:
http://arxiv.org/abs/0711.1851
Autor:
Haagerup, Uffe, Musat, Magdalena
In this paper we consider the following problem: When are the preduals of two hyperfinite (=injective) factors $\M$ and $\N$ (on separable Hilbert spaces) cb-isomorphic (i.e., isomorphic as operator spaces)? We show that if $\M$ is semifinite and $\N
Externí odkaz:
http://arxiv.org/abs/0706.3463
Autor:
Haagerup, Uffe, Musat, Magdalena
We obtain new proofs with improved constants of the Khintchine-type inequality with matrix coefficients in two cases. The first case is the Pisier and Lust-Piquard noncommutative Khintchine inequality for $p=1$, where we obtain the sharp lower bound
Externí odkaz:
http://arxiv.org/abs/math/0611160
Autor:
Musat, Magdalena
We study the operator space UMD property, introduced by Pisier in the context of noncommutative vector-valued Lp-spaces. It is unknown whether the property is independent of p in this setting. We prove that for 1
Externí odkaz:
http://arxiv.org/abs/math/0501033