Skip to main content
10 events
when toggle format what by license comment
Aug 10, 2017 at 15:22 comment added MrUser It might happen, that two different measurable structures produce different sets of measurable sections, regarding the definition I gave above. So the direct integral would not be unique and would depend on the choice of structure. Then, this equality would be true only for suitable choices.
Aug 9, 2017 at 18:31 comment added MrUser A section $s$ is measurable with respect to the "measurable structure" (i.e. to the set of measurable orthonormal sections), iff $<s(\omega),e_i(\omega)>$ is measurable for all $i\in\mathbb{N}$. I guess, that was missing.
Aug 9, 2017 at 18:25 comment added Christian Remling I'm not sure actually I completely understand the definition you summarize, but for me, the elements of a direct integral are measurable (in a suitable sense) functions $s(\omega)$ whose norm, computed in the obvious way, is finite. Then I don't think there will be any problems, though I might be missing something.
Aug 9, 2017 at 18:14 comment added MrUser Yes, i tried that. This isomorphism induces - obviously - a measurable orthonormal section. But you need to show, that the direct integral is independent of the choice of such a section, so that this isomorphism induces the same direct integral, don't you?
Aug 9, 2017 at 17:33 comment added Christian Remling Also, the statement has to be true. If it isn't, then this just means that one has to revise definitions.
Aug 9, 2017 at 17:33 comment added Christian Remling Equality of course must be interpreted as "there is an obvious isomorphism," and I think the only map that comes to mind is the one that sends $s(\omega)=(s_i)_{i\in\mathbb N}(\omega)$ to $(s_i(\omega))_i$ (in other words, it doesn't do anything other than slightly reinterpret). Have you tried if this works?
Aug 9, 2017 at 9:28 history edited Ben McKay CC BY-SA 3.0
spelling, grammar
Aug 9, 2017 at 9:14 history edited MrUser CC BY-SA 3.0
added 62 characters in body
Aug 9, 2017 at 9:13 review First posts
Aug 9, 2017 at 9:16
Aug 9, 2017 at 9:09 history asked MrUser CC BY-SA 3.0