Loeb Extension and Loeb Equivalence II

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Haosui, Duanmu, Schrittesser, David, Weiss, William
Format: Preprint
Published: 2021
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866916504669257728
author Haosui, Duanmu
Schrittesser, David
Weiss, William
author_facet Haosui, Duanmu
Schrittesser, David
Weiss, William
contents The paper answers two open questions that were raised in by Keisler and Sun. The first question asks, if we have two Loeb equivalent spaces $(Ω, \mathcal F, μ)$ and $(Ω, \mathcal G, ν)$, does there exist an internal probability measure $P$ defined on the internal algebra $\mathcal H$ generated from $\mathcal F\cup \mathcal G$ such that $(Ω, \mathcal H, P)$ is Loeb equivalent to $(Ω, \mathcal F, μ)$? The second open problem asks if the $σ$-product of two $σ$-additive probability spaces is Loeb equivalent to the product of the same two $σ$-additive probability spaces. Continuing work in a previous paper, we give a confirmative answer to the first problem when the underlying internal probability spaces are hyperfinite, a partial answer to the first problem for general internal probability spaces, and settle the second question negatively by giving a counter-example. Finally, we show that the continuity sets in the $σ$-algebra of the $σ$-product space are also in the algebra of the product space.
format Preprint
id arxiv_https___arxiv_org_abs_2112_13955
institution arXiv
publishDate 2021
record_format arxiv
spellingShingle Loeb Extension and Loeb Equivalence II
Haosui, Duanmu
Schrittesser, David
Weiss, William
Functional Analysis
Logic
28E05 (primary), 03H05
The paper answers two open questions that were raised in by Keisler and Sun. The first question asks, if we have two Loeb equivalent spaces $(Ω, \mathcal F, μ)$ and $(Ω, \mathcal G, ν)$, does there exist an internal probability measure $P$ defined on the internal algebra $\mathcal H$ generated from $\mathcal F\cup \mathcal G$ such that $(Ω, \mathcal H, P)$ is Loeb equivalent to $(Ω, \mathcal F, μ)$? The second open problem asks if the $σ$-product of two $σ$-additive probability spaces is Loeb equivalent to the product of the same two $σ$-additive probability spaces. Continuing work in a previous paper, we give a confirmative answer to the first problem when the underlying internal probability spaces are hyperfinite, a partial answer to the first problem for general internal probability spaces, and settle the second question negatively by giving a counter-example. Finally, we show that the continuity sets in the $σ$-algebra of the $σ$-product space are also in the algebra of the product space.
title Loeb Extension and Loeb Equivalence II
topic Functional Analysis
Logic
28E05 (primary), 03H05
url https://arxiv.org/abs/2112.13955