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Disgruntled with physics, now a student of mathematics.


Nov
12
comment Submanifold that is closed
@Matt, Rolanda: I think, with those hypotheses, $N$ doesn't need to be closed. Look at proof of Theorem 5.8 in Lee's "Introduction to Smooth Manifolds", where it's shown that the subspace has slice charts. It is enough to know that the subset has the subspace topology and the inclusion is an immersion, for the existence of slice charts. Am I right?
Oct
21
revised Commutator subgroup of rank-2 free group is not finitely generated.
added 6 characters in body
Oct
21
asked Commutator subgroup of rank-2 free group is not finitely generated.
Sep
24
awarded  Autobiographer
Sep
15
awarded  Popular Question
Aug
26
comment From $\left\lVert \sup_{M>M_0} \left| \sum_{k=M_0}^M f_k \right| \right\lVert_2 < \epsilon$ show convergence a.e. of the series.
That's brilliant, thanks.
Aug
26
comment From $\left\lVert \sup_{M>M_0} \left| \sum_{k=M_0}^M f_k \right| \right\lVert_2 < \epsilon$ show convergence a.e. of the series.
Thank you for your answer. I'm trying to understand it... Why does $x\in E_t$ imply $\sup_{M>M_0}|F_{M}-F_{M_0}|>2^{-t-1}$ ?
Aug
26
revised From $\left\lVert \sup_{M>M_0} \left| \sum_{k=M_0}^M f_k \right| \right\lVert_2 < \epsilon$ show convergence a.e. of the series.
deleted 1 character in body
Aug
26
asked From $\left\lVert \sup_{M>M_0} \left| \sum_{k=M_0}^M f_k \right| \right\lVert_2 < \epsilon$ show convergence a.e. of the series.
Aug
18
awarded  Yearling
Aug
13
comment Is it possible for a function to be in $L^p$ for only one $p$?
I'm not following, is $\frac1{x^{1/p}\log^2(x^{1/p})}$ the inverse of $\left(\frac1{x\log^2x}\right)^p$ ?
Aug
12
accepted How to show $ \left(\frac{1-x}{2}\right)^p+\left(\frac{1+x}{2}\right)^p \leq \frac{1+x^p}{2}$
Aug
12
asked How to show $ \left(\frac{1-x}{2}\right)^p+\left(\frac{1+x}{2}\right)^p \leq \frac{1+x^p}{2}$
Aug
12
accepted rationalwiki on “Extraordinary claims require extraordinary evidence”
Aug
11
asked rationalwiki on “Extraordinary claims require extraordinary evidence”
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...