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Sep 19, 2015 at 19:23 comment added Jon Bannon @Jiang: Indeed it is a very nice theorem, and that is a very nice question!
Sep 19, 2015 at 13:12 comment added Jiang @JonBannon, Sometimes, big theorems suffer from the same fate as nuclear bombs: once invented, never used. I like this theorem very much. One reason is that it involves three fundamental objects in II$_1$ factors: the hyperfinite II$_1$ factor $R$, the free group factor $L(F_n)$ and tensor product. And many questions on $R\otimes L(F_n)$ is unanswered, e.g., I think it is not known whether there exists a MASA $A$ in $R\otimes L(F_n)$ such that $A$ is a maximal injective subalgebra. I tend to believe no.
Sep 19, 2015 at 5:51 comment added Jon Bannon @Jiang: That really is a nuclear bomb to kill a fly, though, isn't it?
Sep 18, 2015 at 17:54 comment added Jiang You can apply Ozawa and Popa's theorem proved in the paper arxiv.org/abs/math/0302240.
Sep 18, 2015 at 12:03 comment added Chris Ramsey No worries. I'll take a look.
Sep 18, 2015 at 11:23 comment added Jon Bannon A paywall is keeping me away from the paper, but in McDuff's second paragraph it is outlined: plms.oxfordjournals.org/content/s3-21/3/443.extract If I have a moment I can try to write an answer, but this might take a while.
Sep 17, 2015 at 14:42 comment added Chris Ramsey @JonBannon You are absolutely correct! I was misreading a later paper. Is it easy to see that these are McDuff factors? Perhaps you could give an answer outlining this or giving a reference. Thanks.
Sep 17, 2015 at 0:43 comment added Jon Bannon Hi Chris! It is a fact that if you tensor a $II_1$ factor with a factor with property $\Gamma$, the resulting thing has property $\Gamma$. Therefore all of the McDuff factors (in the 1969 paper) have property $\Gamma$, as they tensorially absorb the hyperfinite II_1 factor (which has \Gamma).
Sep 16, 2015 at 23:09 history edited Chris Ramsey CC BY-SA 3.0
Tried to add some context for why people should care about property Gamma.
Sep 15, 2015 at 23:34 history edited Chris Ramsey CC BY-SA 3.0
Added a sentence.
Sep 15, 2015 at 20:15 history asked Chris Ramsey CC BY-SA 3.0