User celtschk - Mathematics Stack Exchange

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	4,528 reputation	bio	website		visits	member for	10 months
1925 badges		location			seen	Oct 26 '12 at 6:50

20

59

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1

answer

2

kviews

Connected metric spaces with disjoint open balls

metric-spaces connectedness

apr 12 at 13:47 baharampuri 104

98

175

votes

23

answers

7

kviews

Examples of apparent patterns that eventually fail

big-list examples-counterexamples

apr 10 at 3:04 Douglas B. Staple 1,014

181

160

votes

23

answers

10

kviews

Proofs that every mathematician should know?

soft-question big-list

mar 25 at 0:36 Glen O 3,074

11

17

votes

9

answers

794

views

What's a good place to learn Lie groups?

reference-request representation-theory lie-groups

mar 10 at 0:17 Alex Youcis 12.4k

5

12

votes

1

answer

450

views

What is the intution behind the ping-pong lemma?

group-theory geometric-group-theory

feb 18 at 15:30 Sarah Palin 66

35

30

votes

19

answers

5

kviews

Good book/lecture notes about category theory

soft-question reference-request category-theory

dec 31 at 21:54 darij grinberg 881

7

20

votes

17

answers

988

views

Accidents of small $n$

big-list examples-counterexamples

nov 26 at 2:28 MJD 20.7k

1

3

votes

1

answer

288

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Some questions about representations of $SO(6)$

group-theory representation-theory lie-algebras lie-groups mathematical-physics

oct 22 at 19:17 user37376 6

1

vote

0

answers

76

views

A question about a definition of Ricci curvature

differential-geometry curvature

oct 7 at 5:45 M. K. 1,009

1

15

votes

4

answers

518

views

An (apparently) vicious circle in logic

logic

sep 24 at 19:16 Carl Mummert 25.4k

2

9

votes

3

answers

259

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Statements in Euclidean geometry that appear to be true but aren't

geometry trigonometry teaching

sep 23 at 6:15 Jair Taylor 1,325

2

3

votes

2

answers

175

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Fundamental group of $SO(3)$

algebraic-topology lie-groups

sep 21 at 11:45 Marc van Leeuwen 23.6k

3

11

votes

1

answer

272

views

Metric in riemannian Manifold

differential-geometry metric-spaces

sep 19 at 7:17 Sam 6,927

2

6

votes

2

answers

78

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Why is positivity of first entry sufficient for a matrix in $\mathrm{SO}(1,3)$ to be in $\mathrm{SO}^{+}(1,3)$?

group-theory lie-groups general-relativity

sep 14 at 12:16 Marc van Leeuwen 23.6k

5

18

votes

6

answers

674

views

Is this 3D curve a circle?

geometry circle

aug 23 at 11:18 J. M. 38.9k

1

2

votes

0

answers

28

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The definition of simultaneous conjugacy class

group-theory terminology

aug 23 at 6:08 Alexander Gruber 15.1k

1

5

votes

3

answers

299

views

Is the negation of the Gödel sentence always unprovable too?

logic proof-theory incompleteness

aug 20 at 14:51 Nick Kidman 2,592

1

3

votes

1

answer

96

views

use of the word “object”

terminology

aug 17 at 11:46 Simon Markett 5,672

1

7

votes

2

answers

202

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Domain of an operator in functional analysis

functional-analysis definition normed-spaces

aug 15 at 15:25 Matt N. 15.2k

2

3

votes

1

answer

120

views

Convention of digit grouping after decimal point

notation number-systems decimal-expansion convention

aug 15 at 11:38 J. M. 38.9k

1

6

votes

1

answer

204

views

Is there a difference between a model and a representation?

logic representation-theory model-theory

aug 13 at 21:19 Kaveh 1,929

4

6

votes

1

answer

129

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How to identify $SL(2,\mathbb{C})/SU(2)$ and the hyperbolic 3-space?

lie-groups riemannian-geometry hyperbolic-geometry quaternions

aug 12 at 14:50 Eric O. Korman 7,500

3

6

votes

1

answer

157

views

Uniqueness of conjugates of a subgroup.

combinatorics group-theory finite-groups

aug 11 at 18:34 Jack Schmidt 20.1k

1

2

votes

0

answers

82

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Conjugacy classes in $SL(n,q)$

group-theory finite-groups

aug 3 at 13:08 Steve D 5,240

1

5

votes

2

answers

197

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Question about $p$-adic numbers and $p$-adic integers

commutative-algebra algebraic-number-theory p-adic-number-theory

jul 25 at 17:06 Dylan Moreland 13.4k

2

8

votes

1

answer

163

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Selfadjoint compact operator with finite trace

functional-analysis operator-theory

jul 24 at 23:57 paul garrett 10.5k

2

9

votes

2

answers

197

views

Are two subgroups that contain a common element conjugate iff they are conjugate under the normalizer?

group-theory

feb 29 '12 at 16:33 Jack Schmidt 20.1k

celtschk

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