486 reputation
28
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age 25
visits member for 3 years
seen 6 hours ago

Graduate student (Cornell University).


1d
asked The (global) theory of Borel equivalence relations
Jul
14
comment Name/terminology for a relationship between group actions
What is the definition of "inflation" here?
Jul
14
revised Name/terminology for a relationship between group actions
edited tags
Jul
14
asked Name/terminology for a relationship between group actions
Jul
9
accepted How much does the absolute value of an operator behave like an absolute value?
Jul
8
asked How much does the absolute value of an operator behave like an absolute value?
Jul
2
awarded  Curious
Jun
20
awarded  Yearling
Jun
20
asked Characterization of ideals in the bounded operators
Jun
18
accepted Why do the projections in the Calkin algebra not form a lattice?
Jun
17
comment Why do the projections in the Calkin algebra not form a lattice?
Nik, this does seems a bit clearer. Two questions: What is allowing us to find the n(i) as claimed? And what is meant by R/S?
Jun
17
asked Why do the projections in the Calkin algebra not form a lattice?
Jun
12
accepted Is $\ell^\infty$ Polishable?
Jun
11
asked Is $\ell^\infty$ Polishable?
Jun
6
revised A characterization of Mathias reals
added 84 characters in body
Jun
5
comment A characterization of Mathias reals
Right, that seems to work, so each $Y_n$, for $n\geq 1$, has the property that if there exists $t\subset\{m_0,\ldots,m_n\}$ and $Y\subset Y_n$ is such that $(s\cup t,Y)\in D$, then $(s\cup t,Y_n)\in D$. $Y_0$ may not have this property, but in the part of the proof (in the edit) where this is used, we can WLOG assume that $m_0\notin X$.
Jun
5
comment A characterization of Mathias reals
@FrançoisG.Dorais That looks like it works, but how do we go about choosing such a $Y_{n+1}$? As written, the natural thing to do is to take the intersection of the finitely many witnesses (at most one for each $t\subset\{m_0,\ldots,m_n\}$), but this might be empty or finite.
Jun
5
comment A characterization of Mathias reals
@JohnBentin Yes, fixed now.
Jun
5
revised A characterization of Mathias reals
Fixed typo in definition of extension.
Jun
5
comment A characterization of Mathias reals
@FrançoisG.Dorais Is it clear that we can do that in this case? Also, I've added the rest of the proof in an edit, showing where this part of the construction is being used.