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seen Jun 30 at 17:27

Old and slow undergraduate mathematics student.


Jul
2
awarded  Curious
Jul
2
awarded  Inquisitive
Jun
29
comment The set of $x$ where a sequence convergences in terms of set operations
You're right. Thanks again.
Jun
29
accepted The set of $x$ where a sequence convergences in terms of set operations
Jun
29
comment The set of $x$ where a sequence convergences in terms of set operations
thanks a lot. I'm still trying to internalize the proof; I understand the difference between uniform and pointwise continuity. The distinction in the proof is very subtle for me, since between the two intersections in your answer we could still insert a $\bigcup_{n_k\in\mathbb{N}}$, meaning that there exists $n_k$ (the one that was constructed) such that...
Jun
29
comment The set of $x$ where a sequence convergences in terms of set operations
@yoyo Thanks. So I thought. But then I don't understand the proof of Egorov's theorem: en.wikipedia.org/wiki/Egorov's_theorem#Proof Isn't the complement of that set $B$ at the end precisely a set like the one in my post?
Jun
29
asked The set of $x$ where a sequence convergences in terms of set operations
Apr
6
comment Quotient map, quotient topology in Banach spaces
@Rustyn Yes, thanks. I edited.
Apr
6
revised Quotient map, quotient topology in Banach spaces
added 14 characters in body
Apr
6
asked Quotient map, quotient topology in Banach spaces
Mar
25
awarded  Popular Question
Mar
11
accepted Showing that a series in $l_{\infty}$ converges weakly, given a boundedness condition.
Mar
11
comment Showing that a series in $l_{\infty}$ converges weakly, given a boundedness condition.
Right, it's the other way around. Thank you for the clarifications and the answer!
Mar
11
comment Showing that a series in $l_{\infty}$ converges weakly, given a boundedness condition.
Hi there, thanks. Yeah, the original text refers to "the $w^* $ topology induced by the elements of $l_1$", so I assumed they meant the weak topology since $l_1$ is isomorphic to the dual of $l_{\infty}$. It's Lemma 3 in Joram Lindenstrauss' paper "On complemented subspaces of $m$". Could you tell me what they mean by that?
Mar
10
asked Showing that a series in $l_{\infty}$ converges weakly, given a boundedness condition.
Feb
28
revised Showing that an implicitly defined function is analytic on $(0,\infty)$
added 2 characters in body
Feb
28
revised Showing that an implicitly defined function is analytic on $(0,\infty)$
deleted 1 characters in body
Feb
28
asked Showing that an implicitly defined function is analytic on $(0,\infty)$
Feb
22
accepted $ds=\frac{2|dz|}{1-|z|^2}$ conformal invariant of the disc.
Feb
22
comment $ds=\frac{2|dz|}{1-|z|^2}$ conformal invariant of the disc.
Thank you for your explanation. I'm afraid I don't understand yet. For instance, how do you (in practice) compute the angle between two (tangent) vectors measured by the metric $ds$? And same question for the lengths. Sorry for the trouble.