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May 7, 2011 at 5:23 vote accept Andrés E. Caicedo
Apr 13, 2011 at 9:07 answer added 喻 良 timeline score: 7
Nov 19, 2010 at 5:33 comment added Andrés E. Caicedo @Bjørn, you are right, the Reimann-Slaman results do not give examples.
Nov 18, 2010 at 20:24 comment added Bjørn Kjos-Hanssen If we just want a set that contains no largest cone (i.e., no smallest base) then we can take the nonzero degrees, i.e., those $\mathbf a$ with $\mathbf a>\mathbf 0$.
Nov 18, 2010 at 18:31 comment added Bjørn Kjos-Hanssen Reimann and Slaman show that there is a cone consisting of continuously random reals. However they then show that every non-$\Delta^1_1$ real is continuously random. So Kleene's $\mathcal O$ is a fairly natural base for such a cone.
Nov 18, 2010 at 11:17 answer added Bjørn Kjos-Hanssen timeline score: 4
Nov 10, 2010 at 19:05 comment added Andrés E. Caicedo @Henry: Thanks! That's a good place to start.
Nov 10, 2010 at 19:04 history edited Andrés E. Caicedo CC BY-SA 2.5
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Nov 10, 2010 at 18:31 comment added Henry Towsner Slaman and Reimann have some results on random reals (arxiv.org/abs/0707.1390) which use the cone theorem, where it looks like they have some information about the cones, but not an exact base.
Nov 10, 2010 at 17:43 comment added Joel David Hamkins I heard Martin say at a talk once that when he proved his theorem, it was easy to think at first that perhaps it might be used to refute AD, since after all, he knew lots of sets of Turing degrees, and all that was required was to find one such set that neither contained nor omitted a cone. But of course, it didn't turn out that way...
Nov 10, 2010 at 17:22 history asked Andrés E. Caicedo CC BY-SA 2.5