Zobrazeno 1 - 10
of 35
pro vyhledávání: '"Paunescu, Liviu"'
Autor:
Arzhantseva, Goulnara, Paunescu, Liviu
We introduce the notion of action trace as a function naturally associated to a probability measure preserving action of a group on a standard probability space. For countable amenable groups, we characterise stability in permutations using action tr
Externí odkaz:
http://arxiv.org/abs/2304.07656
Autor:
Paunescu, Liviu, Sipos, Andrei
We adapt a continuous logic axiomatization of tracial von Neumann algebras due to Farah, Hart and Sherman in order to prove a metatheorem for this class of structures in the style of proof mining, a research program that aims to obtain the hidden com
Externí odkaz:
http://arxiv.org/abs/2209.01797
Autor:
Munteanu, Radu B., Paunescu, Liviu
Denote by $Sof(G)$ the space of sofic representations of a countable group $G$. This space is known by a result of the second author, to have a convex-like structure. We show that, in this space, minimal faces are extreme points. We then construct un
Externí odkaz:
http://arxiv.org/abs/2107.01236
Autor:
Arzhantseva, Goulnara, Paunescu, Liviu
We introduce notions of a constraint metric approximation and of a constraint stability of a metric approximation. This is done in the language of group equations with coefficients. We give an example of a group which is not constraintly sofic. In bu
Externí odkaz:
http://arxiv.org/abs/1708.00691
Publikováno v:
Ergod. Th. Dynam. Sys. 39 (2019) 3250-3261
We define a subgroup of the universal sofic group, obtained as the normaliser of a separable abelian subalgebra. This subgroup can be obtained as an extension by the group of automorphisms on a standard probability space. We show that each sofic repr
Externí odkaz:
http://arxiv.org/abs/1704.00814
Autor:
Paunescu, Liviu
We study various conditions under which a unitary in an ultraproduct of matrices is conjugated to an ultraproduct of permutations.
Comment: 7 pages
Comment: 7 pages
Externí odkaz:
http://arxiv.org/abs/1605.07101
Autor:
Paunescu, Liviu, Radulescu, Florin
The classic Birkhoff- von Neumann theorem states that the set of doubly stochastic matrices is the convex hull of the permutation matrices. In this paper, we study a generalisation of this theorem in the type $II_1$ setting. Namely, we replace a doub
Externí odkaz:
http://arxiv.org/abs/1506.01685
Autor:
Arzhantseva, Goulnara, Paunescu, Liviu
We prove that the commutator is stable in permutations endowed with the Hamming distance, that is, two permutations that almost commute are near two commuting permutations. Our result extends to $k$-tuples of almost commuting permutations, for any gi
Externí odkaz:
http://arxiv.org/abs/1410.2626
Autor:
Paunescu, Liviu
Publikováno v:
Ergod. Th. Dynam. Sys. 36 (2016) 1596-1615
We provide a complete characterisation of extreme points of the space of sofic representations. We also show that the restriction map $Sof(G,P^{\omega})$ to $Sof(H,P^{\omega})$, where $H\subset G$ is not always surjective. The first part of the paper
Externí odkaz:
http://arxiv.org/abs/1402.5688
Autor:
Paunescu, Liviu
In this article we prove that every automorphism of a universal sofic group is class preserving, i.e. preserves the conjugacy classes
Comment: 9 pages
Comment: 9 pages
Externí odkaz:
http://arxiv.org/abs/1306.3469