Reputation
41,152
Next tag badge:
115/100 score
18/20 answers
Badges
2 43 114
Newest
 Nice Answer
Impact
~546k people reached

3h
revised Inequality for the gradient of a power of absolute value
square doesn't belong
10h
asked Inequality for the gradient of a power of absolute value
1d
awarded  Nice Answer
1d
revised Sufficient Condition for $f\in L^{1}(\mathbb{R}^{d})$ to belong to $L^{2}(\mathbb{R}^{d})$
added 334 characters in body
2d
comment convergence proof without finding 'N'
Don't just push symbols - think about the meaning of what you write. You're claiming that the absolute value of something is strictly less than 0. Does that make sense?
2d
comment space of all lipschitz maps is a polish metric space
Hint: The $x_i$ are supposed to be a countable dense subset of $X$. So given $x$, there is a subsequence $x_{i_k}$ of $x_i$ converging to $x$. So in terms of $f(x_{i_k})$, what would $f(x)$ have to be? (To check this is well defined: if you chose a different subsequence, would you get the same thing?)
2d
answered space of all lipschitz maps is a polish metric space
2d
comment space of all lipschitz maps is a polish metric space
Is there a typo in the definition of $d_L$? I think it should probably be $\sum_i 2^{-(i+1)} d_Y(f(x_i), g(x_i))$.
Aug
25
answered Are there any interesting non-metrics whose open balls generate a topology?
Aug
25
revised Holomorphic function with reals to reals
the mathematician, not the city in Kentucky
Aug
25
revised As of August 2015, is the “set” of all gold medalists in the 2016 Olympics a set?
tags
Aug
25
revised Does $\sin^2(-x)$ simplify?
comment filler text
Aug
25
reviewed Leave Open Does $\sin^2(-x)$ simplify?
Aug
25
reviewed Leave Open Why is there 15 principal minors in 4 x 4 matrix?
Aug
24
revised If $f_k \to f$ a.e. and the $L^p$ norms converge, then $f_k \to f$ in $L^p$
title, tags
Aug
24
revised Independence of existence of inaccessible cardinals
more tags
Aug
24
answered piecewise weak convergence in $C[0,1]$
Aug
23
comment A-noncompact, Does there **always** exist a continuous function $f: A \to \mathbb R$ which is bounded but does not assume extreme values?
If $A$ is allowed to be an arbitrary topological space, not necessarily a subset of $\mathbb{R}$, then we can take $A = \omega_1$ to be the first uncountable ordinal space. This space is not compact but every continuous real-valued function assumes extreme values.
Aug
23
comment $f$ and $f'$ are in $L^1 (\Bbb R)$. Prove that $\int_{-\infty}^{\infty} f' (x)dx=0$.
However, this question has certainly been asked here before. If I can find it I'll add a link.
Aug
23
comment $f$ and $f'$ are in $L^1 (\Bbb R)$. Prove that $\int_{-\infty}^{\infty} f' (x)dx=0$.
Please edit your previous question rather than adding a new one. When the previous question is improved it can be reopened.