1,276 reputation
617
bio website
location
age
visits member for 3 years, 3 months
seen Jan 27 at 14:19

Jan
27
comment When two projections in a C*-algebra are “almost” Murray-von Neumann equivalent, they are equivalent
Intuitively, maybe we can first show that when $aa^*$ is close to $p$, then the range projection of $aa^*$, denote it by $r_1$, is close to $p$, maybe the assumption is strong enough to imply $||r_1-p||<1$, so they are unitary equivalent, do the same thing for $q$, note that $r_1, r_2$ are unitary equivalent.
Jan
26
accepted find a special group
Jan
26
asked find a special group
Jan
25
comment one end group with positve first Betti number$\beta^{(2)}_1(G)>0$
Thanks again! It is good to know that...
Jan
24
comment one end group with positve first Betti number$\beta^{(2)}_1(G)>0$
Thanks, to see the surface groups have one end, if my understanding is right, just look at the Cayley group(some tiling of the plane); is there any way to see directly that the surface groups could not be of the form predicted by the Stalling theorem? Btw, how to see in (2), $B^1$ is not closed?...
Jan
24
accepted one end group with positve first Betti number$\beta^{(2)}_1(G)>0$
Jan
23
asked one end group with positve first Betti number$\beta^{(2)}_1(G)>0$
Jan
22
accepted Extending a measurable map $f: G \to \mathbb{R}/\mathbb{Z}$ to a continuous group homomorphism
Jan
17
accepted Any infinite property (T) subgroup of $Aut(F_n)$?
Jan
16
asked Any infinite property (T) subgroup of $Aut(F_n)$?
Dec
21
awarded  Constituent
Dec
16
accepted commuting subsets in a group
Dec
16
comment commuting subsets in a group
I mean for any $(t_1, t_2)\in K\times K$. As usual, they can be the same or different.
Dec
16
revised commuting subsets in a group
Clarify inaccuracy
Dec
16
revised commuting subsets in a group
Fix typo
Dec
16
asked commuting subsets in a group
Dec
11
awarded  Caucus
Dec
7
accepted Whitehead double
Dec
7
asked Whitehead double
Nov
28
accepted evaluate two sums in analytic number theory