Question

Spotting error in proof for $(A \cup B)^\circ = A^\circ \cup B^\circ$

score 83 · Answer 1 · 2026-04-02 01:39:34

83

Views

Spotting error in proof for $(A \cup B)^\circ = A^\circ \cup B^\circ$

Published on 02 Apr 2026 - 1:39

score 106 · Answer 2 · 2026-03-25 04:42:35

106

Views

Why are facts proven in the (infinite) product topology also true for finite products?

Published on 25 Mar 2026 - 4:42

score 83 · Answer 3 · 2026-03-25 08:01:33

83

Views

Are the laminations of Julia sets of the same period the same?

Published on 25 Mar 2026 - 8:01

score 45 · Answer 4 · 2026-03-28 03:01:10

45

Views

Existence of an infinite countable compact subset of $\mathbf{R}$

Published on 28 Mar 2026 - 3:01

score 427 · Answer 5 · 2026-03-30 14:12:02

427

Views

Brouwer Fixed Point, Jordan Curve, Hairy Ball and Borsuk-Ulam theorems - Characterization of topology of Euclidean spaces

Published on 30 Mar 2026 - 14:12

score 113 · Answer 6 · 2026-03-25 09:38:45

113

Views

Classify, except isomorphism, all the covering spaces on $\mathbb{S}^1$ with three branches such that the total space is not necessarily arc-connected

Published on 25 Mar 2026 - 9:38

score 41 · Answer 7 · 2026-03-25 03:21:18

41

Views

Is there $T_2$- space $X$ and a group $G$ such that $X_G$ is not $T_2$ space?

Published on 25 Mar 2026 - 3:21

score 409 · Answer 8 · 2018-05-06 18:14:31

409

Views

Show that T is a not a topology on X

Published on 06 May 2018 - 18:14

score 235 · Answer 9 · 2026-03-28 04:45:23

235

Views

$f:X\to Y$ continuous, $X$ compact, $g:Y\to Z$ such that $g\circ f$ is continuous $\implies$ $g$ is continuous

Published on 28 Mar 2026 - 4:45

score 1.7k · Answer 10 · 2018-05-06 20:28:47

1.7k

Views

Every open and closed set is $G_{\delta}$ and $ F_{\sigma}$

Published on 06 May 2018 - 20:28

score 830 · Answer 11 · 2026-03-26 04:51:24

830

Views

Characterization of Topology

Published on 26 Mar 2026 - 4:51

score 41 · Answer 12 · 2018-05-06 23:26:51

41

Views

Showing $\{(z - 2, z + 2): z \in \mathbb Z\}$ is an open cover of $[-3, 3]$

Published on 06 May 2018 - 23:26

score 139 · Answer 13 · 2026-03-25 15:52:38

139

Views

Is this subspace of $\ell_\infty$ a Banach space?

Published on 25 Mar 2026 - 15:52

score 283 · Answer 14 · 2018-05-07 01:13:43

283

Views

Open subsets of $\mathbf{R}^n$

Published on 07 May 2018 - 1:13

score 107 · Answer 15 · 2018-05-07 01:39:55

107

Views

What are the interior and boundary of $\Bbb R^2 - \{(x,sin(1/x))|x>0\}$ in $\Bbb R^2$?

Published on 07 May 2018 - 1:39

List Question

Spotting error in proof for $(A \cup B)^\circ = A^\circ \cup B^\circ$

Why are facts proven in the (infinite) product topology also true for finite products?

Are the laminations of Julia sets of the same period the same?

Existence of an infinite countable compact subset of $\mathbf{R}$

Brouwer Fixed Point, Jordan Curve, Hairy Ball and Borsuk-Ulam theorems - Characterization of topology of Euclidean spaces

Classify, except isomorphism, all the covering spaces on $\mathbb{S}^1$ with three branches such that the total space is not necessarily arc-connected

Is there $T_2$- space $X$ and a group $G$ such that $X_G$ is not $T_2$ space?

Show that T is a not a topology on X

$f:X\to Y$ continuous, $X$ compact, $g:Y\to Z$ such that $g\circ f$ is continuous $\implies$ $g$ is continuous

Every open and closed set is $G_{\delta}$ and $ F_{\sigma}$

Characterization of Topology

Showing $\{(z - 2, z + 2): z \in \mathbb Z\}$ is an open cover of $[-3, 3]$

Is this subspace of $\ell_\infty$ a Banach space?

Open subsets of $\mathbf{R}^n$

What are the interior and boundary of $\Bbb R^2 - \{(x,sin(1/x))|x>0\}$ in $\Bbb R^2$?

Trending Questions

Popular # Hahtags

Popular Questions