Automorphism–invariant measures on ℵ0-categorical structures without the independence property

1996 ◽  
Vol 61 (2) ◽  
pp. 640-652
Author(s):  
Douglas E. Ensley

AbstractWe address the classification of the possible finitely-additive probability measures on the Boolean algebra of definable subsets of M which are invariant under the natural action of Aut(M). This pursuit requires a generalization of Shelah's forking formulas [8] to “essentially measure zero” sets and an application of Myer's “rank diagram” [5] of the Boolean algebra under consideration. The classification is completed for a large class of ℵ0-categorical structures without the independence property including those which are stable.

1989 ◽  
Vol 01 (02n03) ◽  
pp. 235-290 ◽  
Author(s):  
SHUICHIRO MAEDA

A state ϕ on a von Neumann algebra A is a positive linear functional on A with ϕ(1) = 1, and the restriction of ϕ to the set of projections in A is a finitely additive probability measure. Recently it was proved that if A has no type I 2 summand then every finitely additive probability measure on projections can be extended to a state on A. Here we give precise and complete arguments for proving this result.


2017 ◽  
Vol 153 (12) ◽  
pp. 2482-2533
Author(s):  
Alexander I. Bufetov ◽  
Yanqi Qiu

Let$F$be a non-discrete non-Archimedean locally compact field and${\mathcal{O}}_{F}$the ring of integers in$F$. The main results of this paper are the classification of ergodic probability measures on the space$\text{Mat}(\mathbb{N},F)$of infinite matrices with entries in$F$with respect to the natural action of the group$\text{GL}(\infty ,{\mathcal{O}}_{F})\times \text{GL}(\infty ,{\mathcal{O}}_{F})$and the classification, for non-dyadic$F$, of ergodic probability measures on the space$\text{Sym}(\mathbb{N},F)$of infinite symmetric matrices with respect to the natural action of the group$\text{GL}(\infty ,{\mathcal{O}}_{F})$.


2011 ◽  
Vol 169 (1) ◽  
pp. 65-90 ◽  
Author(s):  
Aleksandar Perović ◽  
Zoran Ognjanović ◽  
Miodrag Rašković ◽  
Dragan Radojević

Author(s):  
M Pourmahdian ◽  
R Zoghifard

Abstract This paper provides some model-theoretic analysis for probability (modal) logic ($PL$). It is known that this logic does not enjoy the compactness property. However, by passing into the sublogic of $PL$, namely basic probability logic ($BPL$), it is shown that this logic satisfies the compactness property. Furthermore, by drawing some special attention to some essential model-theoretic properties of $PL$, a version of Lindström characterization theorem is investigated. In fact, it is verified that probability logic has the maximal expressive power among those abstract logics extending $PL$ and satisfying both the filtration and disjoint unions properties. Finally, by alternating the semantics to the finitely additive probability models ($\mathcal{F}\mathcal{P}\mathcal{M}$) and introducing positive sublogic of $PL$ including $BPL$, it is proved that this sublogic possesses the compactness property with respect to $\mathcal{F}\mathcal{P}\mathcal{M}$.


2013 ◽  
Vol 59 (1-2) ◽  
pp. 119-124 ◽  
Author(s):  
Viktor Verbovskiy

1991 ◽  
Vol 56 (1) ◽  
pp. 103-107
Author(s):  
Maxim R. Burke

AbstractWe investigate the cofinality of the partial order κ of functions from a regular cardinal κ into the ideal of Lebesgue measure zero subsets of R. We show that when add () = κ and the covering lemma holds with respect to an inner model of GCH, then cf (κ) = max{cf(κκ), cf([cf()]κ)}. We also give an example to show that the covering assumption cannot be removed.


Sign in / Sign up

Export Citation Format

Share Document