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May
8
comment Express unit sphere as countable union of great circles?
@Misakov The version I state is equivalent to yours if you replace union with intersection (see e.g. here. In your other comment, if you replace dense with open dense in the conclusion then yes, it seems to me that you can argue like that.
May
8
comment Express unit sphere as countable union of great circles?
@Misakov I elaborated on this hint. Maybe it helps you answer your comment here.
May
8
answered Express unit sphere as countable union of great circles?
May
3
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Apr
29
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Apr
27
comment $p$-adic completion of integers
@user135520 Which sequence are you talking about? It's quite some time since I wrote this post...
Apr
24
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Apr
17
revised Weak convergence in $D^{1,p}(\mathbb{R}^n)$ and in $\mathcal{M}(\mathbb{R}^n)$
edited title
Apr
10
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Mar
30
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Mar
22
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Mar
16
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Mar
7
comment Intersection of all neighborhoods of zero is a subgroup
@TobiasKildetoft Thank you for your comment!
Feb
27
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Feb
26
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Feb
20
comment Are these linear maps bounded?
Seriously: first you pretend you can solve the exercise by "giving" "overgenerous hints" and when I press you for an answer you admit you can't solve it either.
Feb
20
comment Are these linear maps bounded?
I think is clear that the idea of the exercise is to give an explicit example.
Feb
20
comment Are these linear maps bounded?
What's an example of an oscillating function with compact support?
Feb
20
comment Are these linear maps bounded?
Yes, I would like to see an example of a sequence of $f_n$ with $\|f_n\|_\infty \le 1$ and $\|f_n'\|_\infty$ unbounded. Because that's what I've been trying to construct for the past 30 minutes but have not managed. I believe this is what's difficult about this exercise.
Feb
19
comment Are these linear maps bounded?
I also rolled back an entirely unnecessary edit.