Zobrazeno 1 - 10
of 24
pro vyhledávání: '"Jahel, Colin"'
Autor:
Jahel, Colin, Perruchaud, Pierre
The classical de Finetti Theorem classifies the $\mathrm{Sym}(\mathbb N)$-invariant probability measures on $[0,1]^{\mathbb N}$. More precisely it states that those invariant measures are combinations of measures of the form $\nu^{\otimes\mathbb N}$
Externí odkaz:
http://arxiv.org/abs/2410.22930
We obtain a complete classification of the continuous unitary representations of the isometry group of the rational Urysohn space $\mathbb{Q}\mathbb{U}$. As a consequence, we show that Isom$(\mathbb{Q}\mathbb{U})$ has property (T). We also derive sev
Externí odkaz:
http://arxiv.org/abs/2410.01725
We study the problem of when, given a homogeneous structure $M$ and a space $S$ of expansions of $M$, every $\mathrm{Aut}(M)$-invariant probability measure on $S$ is exchangeable (i.e. $S_\infty$-invariant). We define a condition of $k$-overlap close
Externí odkaz:
http://arxiv.org/abs/2408.08370
Countable $\mathcal{L}$-structures $\mathcal{N}$ whose isomorphism class supports a permutation invariant probability measure in the logic action have been characterized by Ackerman-Freer-Patel to be precisely those $\mathcal{N}$ which have no algebr
Externí odkaz:
http://arxiv.org/abs/2408.07454
We present a proof of the extension property for partial automorphisms (EPPA) for classes of finite $n$-partite tournaments for $n \in \{2,3,\ldots,\omega\}$, and for the class of finite semigeneric tournaments. We also prove that the generic $\omega
Externí odkaz:
http://arxiv.org/abs/2401.12153
Autor:
Jahel, Colin, Joseph, Matthieu
Let $G$ be a closed permutation group on a countably infinite set $\Omega$, which acts transitively but not highly transitively. If $G$ is oligomorphic, has no algebraicity and weakly eliminates imaginaries, we prove that any probability measure pres
Externí odkaz:
http://arxiv.org/abs/2307.06253
Autor:
Bodirsky, Manuel, Jahel, Colin
We study the first-order almost-sure theories for classes of finite structures that are specified by homomorphically forbidding a set $\mathcal{F}$ of finite structures. If $\mathcal{F}$ consists of undirected graphs, a full description of these theo
Externí odkaz:
http://arxiv.org/abs/2204.01404
Autor:
Jahel, Colin, Tsankov, Todor
Let $M$ be an $\aleph_0$-categorical structure and assume that $M$ has no algebraicity and has weak elimination of imaginaries. Generalizing classical theorems of de Finetti and Ryll-Nardzewski, we show that any ergodic, $\operatorname{Aut}(M)$-invar
Externí odkaz:
http://arxiv.org/abs/2007.00281
Autor:
Jahel, Colin, Zucker, Andy
Let $G$ be a locally compact Polish group. A metrizable $G$-flow $Y$ is called model-universal if by considering the various invariant probability measures on $Y$, we can recover every free action of $G$ on a standard Lebesgue space up to isomorphism
Externí odkaz:
http://arxiv.org/abs/2006.01710
We prove that for every $n\geq 2$ the class of all finite $n$-partite tournaments (orientations of complete $n$-partite graphs) has the extension property for partial automorphisms, that is, for every finite $n$-partite tournament $G$ there is a fini
Externí odkaz:
http://arxiv.org/abs/1903.07476