Zobrazeno 1 - 10
of 174
pro vyhledávání: '"Kechris, Alexander S."'
Autor:
Kechris, Alexander S., Wolman, Michael
Standard results in descriptive set theory provide sufficient conditions for a set $P \subseteq \mathbb{N}^\mathbb{N} \times \mathbb{N}^\mathbb{N}$ to admit a Borel uniformization, namely, when $P$ has ''small'' sections or ''large'' sections. We con
Externí odkaz:
http://arxiv.org/abs/2405.15111
Nadkarni's Theorem asserts that for a countable Borel equivalence relation (CBER) exactly one of the following holds: (1) It has an invariant Borel probability measure or (2) it admits a Borel compression, i.e., a Borel injection that maps each equiv
Externí odkaz:
http://arxiv.org/abs/2305.14518
Publikováno v:
Ergod. Th. Dynam. Sys. 42 (2022) 180-194
It is a long-standing open question whether every Polish group that is not locally compact admits a Borel action on a standard Borel space whose associated orbit equivalence relation is not essentially countable. We answer this question positively fo
Externí odkaz:
http://arxiv.org/abs/1909.08110
In this paper we develop a co-induction operation which transforms an invariant random subgroup of a group into an invariant random subgroup of a larger group. We use this operation to construct new continuum size families of non-atomic, weakly mixin
Externí odkaz:
http://arxiv.org/abs/1806.08590
Publikováno v:
J. Symbolic Logic, 2018
We study the complexity of the isomorphism relation for various classes of closed subgroups of the group of permutations of the natural numbers. We use the setting of Borel reducibility between equivalence relations on Polish spaces. For profinite, l
Externí odkaz:
http://arxiv.org/abs/1705.08081
Autor:
Burton, Peter, Kechris, Alexander S.
We survey recent progress in the theory of weak containment of measure preserving group actions.
Comment: Survey article. Final version - to appear in Ergodic Theory and Dynamical Systems
Comment: Survey article. Final version - to appear in Ergodic Theory and Dynamical Systems
Externí odkaz:
http://arxiv.org/abs/1611.07921
We show that weak containment of free ergodic measure-preserving actions of $\mathbf{F}_\infty$ is not equivalent to weak containment of the corresponding Koopman representations. This result is based on the construction of an invariant random subgro
Externí odkaz:
http://arxiv.org/abs/1608.01331
Autor:
Chen, Ruiyuan, Kechris, Alexander S.
For a class $\mathcal K$ of countable relational structures, a countable Borel equivalence relation $E$ is said to be $\mathcal K$-structurable if there is a Borel way to put a structure in $\mathcal K$ on each $E$-equivalence class. We study in this
Externí odkaz:
http://arxiv.org/abs/1606.01995
Publikováno v:
J. Europ. Math. Soc. 16 (2014), 2059--2095
We show that the only random orderings of finite graphs that are invariant under isomorphism and induced subgraph are the uniform random orderings. We show how this implies the unique ergodicity of the automorphism group of the random graph. We give
Externí odkaz:
http://arxiv.org/abs/1208.2389