175 reputation
7
bio website
location
age
visits member for 2 years, 11 months
seen Aug 24 at 23:02

Jul
2
awarded  Curious
Apr
15
comment Whether convergence in L2 norm implies convergence a.e.?
Thank you very much, @Potato.
Apr
15
accepted Whether convergence in L2 norm implies convergence a.e.?
Apr
15
comment Whether convergence in L2 norm implies convergence a.e.?
Thank you very much, @julien. I am not sure if I should delete the post.
Apr
15
asked Whether convergence in L2 norm implies convergence a.e.?
Apr
3
accepted How to determine the convergence of this improper integral?
Apr
3
comment How to determine the convergence of this improper integral?
I like your answer also. It looks like a textbook.
Apr
3
comment How to determine the convergence of this improper integral?
Great, @Caran. Thank you so much!
Apr
3
comment How to determine the convergence of this improper integral?
I plot it. It has periodic downward peaks.
Apr
3
comment How to determine the convergence of this improper integral?
I hope to get things like $\int_0^\infty e^{-x}xdx$, but I cannot find a way.
Apr
3
asked How to determine the convergence of this improper integral?
Mar
24
comment Why finitely generated abelian group is free?
Thank you so much, @YACP. Now I am clear.
Mar
24
comment Why finitely generated abelian group is free?
Thank you, @Babak. I have seen that theorem.
Mar
24
accepted Why finitely generated abelian group is free?
Mar
24
comment Why finitely generated abelian group is free?
Thank you very much, @YACP. I like your answer. Could you explain a little about how to get this? $G\simeq \mathbb{Z}^n/\ker(f)\simeq \mathbb Zy_1\oplus\cdots\oplus\mathbb Zy_n/\mathbb Zd_1y_1\oplus\cdots\oplus\mathbb Zd_ry_r$.
Mar
23
revised Why finitely generated abelian group is free?
deleted 65 characters in body
Mar
23
comment Why finitely generated abelian group is free?
Thank Ittay (I can use FTFGAG), @Babak, and Martin for your reference and hint.
Mar
23
asked Why finitely generated abelian group is free?
Mar
9
comment If $f=\chi_{\{0\}}$, how to show $\|f\|_\infty=1$?
Thank you so much, @Isaac. It is a very nice proof.
Mar
9
accepted If $f=\chi_{\{0\}}$, how to show $\|f\|_\infty=1$?