Skip to main content

Timeline for nonhausdorff dimension

Current License: CC BY-SA 2.5

14 events
when toggle format what by license comment
Mar 22, 2013 at 15:13 answer added John Rognes timeline score: 5
Apr 14, 2012 at 21:34 answer added Douglas Somerset timeline score: 0
Jan 9, 2010 at 15:06 answer added Joel David Hamkins timeline score: 11
Jan 9, 2010 at 0:23 comment added Pete L. Clark BTW, could you please capitalize the first letter in each sentence? This would make your posts easier to read.
Jan 9, 2010 at 0:21 answer added Pete L. Clark timeline score: 5
Jan 8, 2010 at 22:50 comment added Mariano Suárez-Álvarez Take transitive closures at each step just as you did to define $\sim$.
Jan 8, 2010 at 22:50 history edited Martin Brandenburg CC BY-SA 2.5
deleted 48 characters in body; added 91 characters in body
Jan 8, 2010 at 22:49 comment added Martin Brandenburg @mariano: are you sure? this does not look transitive.
Jan 8, 2010 at 22:40 comment added Mariano Suárez-Álvarez I guess you want something more than the following recursive description: $x\sim_{\alpha+1}y$ iff given $U$ and $V$ open neighborhoods of $x$ and $y$, there exists $x'\in U$ and $y'\in V$ such that $x'\sim_{\alpha} y'$.
Jan 8, 2010 at 22:19 comment added Jonas Meyer My mistake, I should have read more carefully. The parenthetical remark threw me off, because the generating relation was being defined where I thought the equivalence relation was intended. But yes, it should have been clear. Thanks.
Jan 8, 2010 at 21:57 comment added Pete L. Clark @JM: He didn't claim it was an equivalence relation; he said "generated by", i.e., the smallest equivalence relation containing the given relation.
Jan 8, 2010 at 21:51 comment added Jonas Meyer Furthermore I don't think what you describe is an equivalence relation. E.g. in the topology on {a,b,c,d,e} with subbasis {{a,d,e},{b,d},{c,e}}, a~b and a~c but ¬(b~c).
Jan 8, 2010 at 21:23 comment added Pete L. Clark "Topological indistinguishability" usually refers to a different, finer, equivalence relation: $x \sim y$ iff $x$ and $y$ have exactly the same neighborhoods. The quotient by this relation is called the Kolmogorov quotient and is the universal $T_0$-space mapped to by the given space. Thus your terminology is potentially confusing to readers, and I recommend that you adjust it.
Jan 8, 2010 at 21:16 history asked Martin Brandenburg CC BY-SA 2.5