User HenrikRüping

54 votes

4 answers

6k views

Are the rationals homeomorphic to any power of the rationals?

asked May 26, 2010 at 12:22

36 votes

1 answer

3k views

Collatz conjecture for numbers of th form $2^n +1$

asked Jan 4, 2011 at 14:39

32 votes

3 answers

4k views

Which spaces are inverse limits of discrete spaces ?

asked Feb 16, 2010 at 10:34

26 votes

7 answers

2k views

Tetrahedra with prescribed face angles

asked Feb 24, 2010 at 7:54

22 votes

5 answers

2k views

When is a extension of $\mathbb{Z}$ by a free group a CAT(0) group?

asked Feb 1, 2011 at 11:11

19 votes

3 answers

5k views

Is a inverse limit of compact spaces again compact ?

asked Mar 18, 2010 at 13:35

19 votes

2 answers

1k views

Are there space filling curves for the Hilbert cube?

asked Aug 9, 2010 at 8:23

17 votes

1 answer

701 views

Outer automorphisms of finite extensions

asked Apr 15, 2011 at 12:48

15 votes

4 answers

3k views

Automorphisms of $SL_n(\mathbb{Z})$

asked Mar 3, 2011 at 10:11

15 votes

2 answers

1k views

infinite dimensional CAT(0) groups

asked Jan 5, 2012 at 13:23

15 votes

0 answers

753 views

Are all these groups CAT(0) groups?

asked Sep 7, 2010 at 11:58

13 votes

4 answers

1k views

Can Lipschitz maps increase the Lebesgue dimension ?

asked Aug 24, 2010 at 9:57

13 votes

2 answers

364 views

Finding hyperbolic metrics by approximation

asked Apr 16, 2012 at 9:33

12 votes

1 answer

441 views

Does this group act geometrically on a Median space?

asked Dec 10, 2012 at 12:57

12 votes

2 answers

573 views

Self homeomorphisms of $S^2\times S^2$

asked Oct 11, 2010 at 15:17

12 votes

2 answers

950 views

Borromean braids

asked Nov 11, 2010 at 10:04

12 votes

4 answers

1k views

Topologizing free abelian groups

asked Mar 30, 2010 at 13:20

12 votes

3 answers

533 views

Small simplicial set models for BG

asked Jul 22, 2021 at 14:57

11 votes

1 answer

502 views

Is the norm element characteristic in modular group rings?

asked Nov 26, 2018 at 11:24

11 votes

4 answers

898 views

Are there unique geodesics in the NIL and SOL geometry?

asked Sep 29, 2010 at 10:53

11 votes

1 answer

536 views

Can dividing out a group action can increase the Lebesgue dimension ?

asked Oct 4, 2010 at 14:43

11 votes

1 answer

836 views

Are these abelian groups free?

asked Mar 8, 2012 at 15:32

9 votes

1 answer

689 views

Is every solvable subgroup of $GL(n,\mathbb{Z})$ polycyclic?

asked Oct 25, 2011 at 12:12

9 votes

3 answers

1k views

Are subgroups of hyperbolic groups quasiisometrically embedded ?

asked Dec 7, 2011 at 13:25

9 votes

1 answer

345 views

On which space does $GL_n(F_p[X])$ act nicely?

asked Jun 27, 2011 at 12:10

8 votes

1 answer

916 views

geodesic 2-dimensional submanifolds of a Riemannian manifold [duplicate]

asked Feb 7, 2011 at 13:53

8 votes

1 answer

1k views

Is there an elementary way to show the triangular inequality for this expression ?

asked Feb 11, 2011 at 11:10

8 votes

5 answers

1k views

Analogues of the dihedral group

asked Jan 3, 2012 at 13:17

8 votes

2 answers

487 views

Which groups have nice compactifications ?

asked Sep 22, 2010 at 14:58

8 votes

1 answer

223 views

local structure of free $\mathbb{R}$ actions

asked Nov 4, 2010 at 10:05

Stack Exchange Network

87 Questions

Are the rationals homeomorphic to any power of the rationals?

Collatz conjecture for numbers of th form $2^n +1$

Which spaces are inverse limits of discrete spaces ?

Tetrahedra with prescribed face angles

When is a extension of $\mathbb{Z}$ by a free group a CAT(0) group?

Is a inverse limit of compact spaces again compact ?

Are there space filling curves for the Hilbert cube?

Outer automorphisms of finite extensions

Automorphisms of $SL_n(\mathbb{Z})$

infinite dimensional CAT(0) groups

Are all these groups CAT(0) groups?

Can Lipschitz maps increase the Lebesgue dimension ?

Finding hyperbolic metrics by approximation

Does this group act geometrically on a Median space?

Self homeomorphisms of $S^2\times S^2$

Borromean braids

Topologizing free abelian groups

Small simplicial set models for BG

Is the norm element characteristic in modular group rings?

Are there unique geodesics in the NIL and SOL geometry?

Can dividing out a group action can increase the Lebesgue dimension ?

Are these abelian groups free?

Is every solvable subgroup of $GL(n,\mathbb{Z})$ polycyclic?

Are subgroups of hyperbolic groups quasiisometrically embedded ?

On which space does $GL_n(F_p[X])$ act nicely?

geodesic 2-dimensional submanifolds of a Riemannian manifold [duplicate]

Is there an elementary way to show the triangular inequality for this expression ?

Analogues of the dihedral group

Which groups have nice compactifications ?

local structure of free $\mathbb{R}$ actions