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JonSK
  • Member for 6 years, 7 months
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5 votes
2 answers
842 views

Immersions are open maps if dimensions are equal

4 votes
1 answer
475 views

If $M$ is a connected manifold, does $M\setminus\{p\}$ have finitely many components?

4 votes
1 answer
132 views

How to show if these spaces are metrizable?

4 votes
1 answer
202 views

Product of perfect maps is perfect

3 votes
1 answer
82 views

Proving that $\mathbb{R}P^n$ is a manifold

3 votes
1 answer
377 views

Alternative definitions of residue at infinity

3 votes
2 answers
148 views

If $\mu(A)<\delta$ then $\sup_{f\in\mathcal{F}}\int_A|f|d\mu<\epsilon$

2 votes
1 answer
297 views

Prove that $\int fg=\lim_{n\to\infty}\int f_ng$ [duplicate]

2 votes
1 answer
169 views

Extending differentiable functions to the whole manifold

2 votes
1 answer
305 views

Is it true that $Fr(A\cup B)=Fr(A)\cup Fr(B)$ if $A\cap\overline{B}=\emptyset$ and $\overline{A}\cap B=\emptyset$?

2 votes
1 answer
153 views

Show that $C=\cap_{s\in S}C_s$ is compact, connected and non-empty. [duplicate]

2 votes
0 answers
325 views

Showing that $\{(x,|x|):x\in\mathbb{R}\}$ is not the image of an immersion [duplicate]

2 votes
1 answer
48 views

Isometries of metric spaces $Z=X\cup (X\times\mathbb{R})$ (corrected)

1 vote
0 answers
616 views

How to show this atlas is maximal on the sphere $S^n$?

1 vote
2 answers
110 views

If we have a basis $\{f_1,...,f_n\}$ of $V^*$, can we give a basis $\{x_1,...,x_n\}$ of $V$?

1 vote
1 answer
37 views

Isometries of $(\mathbb{R},\min\{|\cdot|,1\})$

1 vote
1 answer
124 views

If $X$ is locally compact, $U$ is open and $F$ is closed, is $U\cap F$ locally compact?

1 vote
1 answer
144 views

A particular case of Sard's Theorem

1 vote
2 answers
143 views

Uniform metric topology is contained in box topology

1 vote
2 answers
178 views

Calculating $\int_{|z|=2}\frac{e^{1/z^2}}{1-z}dz$

1 vote
1 answer
42 views

Showing that $\lim_{t\to\infty}\left(\sup_{n\in\mathbb{N}}\int_{\{x:f_n(x)\ge t\}}|f_n|d\mu\right)=0.$

1 vote
1 answer
106 views

If $\lambda, v$ are two measures, is $\{A:v(A)=\lambda(A)\}$ a $\sigma-$algebra?

0 votes
1 answer
109 views

Show that $|f(z)|\le M\frac{\prod_{k=1}^n|z-z_k|}{\prod_{k=1}^n|z+\overline{z_k}|}$ on the right half plane

0 votes
1 answer
443 views

Proving that the tangent space of $\Delta$ is the diagonal of $T_pM\times T_pM$

0 votes
1 answer
70 views

If $G$ is a discrete topological group, is $(G,X,\theta)$ a $G$-space?

0 votes
1 answer
289 views

Cluster and limit points of $z$-ultrafilters

0 votes
1 answer
332 views

Exhaustion by compact sets in $\mathbb{C}^n$