current community
chat
MathOverflow
MathOverflow Meta
your communities
Sign up
or
log in
to customize your list.
more stack exchange communities
company blog
Stack Exchange
Inbox
Reputation and Badges
sign up
log in
tour
help
Tour
Start here for a quick overview of the site
Help Center
Detailed answers to any questions you might have
Meta
Discuss the workings and policies of this site
MathOverflow
Questions
Tags
Users
Badges
Unanswered
Ask Question
Profile
Activity
HJRW
Meta User
Network Profile
Reputation
13,745
13.7k
9.5k
5.3k
2012
2013
2014
2015
Top tag
gr.group-theory
Next privilege
15,000 Rep.
Protect questions
Badges
2
39
98
Newest
Yearling
Next badge
75/100
Proofreader
Impact
~
306k
people reached
24 posts edited
59 helpful flags
3,338 votes cast
summary
answers
questions
tags
badges
favorites
bounties
reputation
all actions
193
Answers
newest
activity
votes
33
What are your favorite instructional counterexamples?
Mar 2 '10 at 19:00
32
What are some of the big open problems in 3-manifold theory?
Aug 22 '10 at 22:07
28
Most interesting mathematics mistake?
Dec 15 '09 at 19:14
25
Mapping from a finite index subgroup onto the whole group
Mar 2 '12 at 13:19
25
finite generated group realized as fundamental group of manifolds
Feb 16 '10 at 3:12
24
Primes occurring as orders of elements of a finitely presented group
Feb 8 '13 at 13:03
21
〈x,y : x^p = y^p = (xy)^p = 1〉
Apr 24 '10 at 23:18
20
Can a group be a universal Turing machine?
Feb 14 '12 at 10:01
19
Fundamental groups of closed hyperbolic 3-manifolds are freely indecomposable
Mar 9 '11 at 4:33
17
Is there a finitely presented group with infinite homology over $\mathbb{Q}$?
Aug 7 '14 at 5:09
16
When is a extension of $\mathbb{Z}$ by a free group a CAT(0) group?
Feb 1 '11 at 15:46
16
How helpful is non-standard analysis?
Feb 25 '10 at 0:38
16
Fundamental group of 3-manifold with boundary
Nov 19 '09 at 18:04
15
A single paper everyone should read?
Nov 8 '09 at 5:18
15
Residual finiteness: why do we care?
Feb 28 at 4:30
14
Is it decidable whether or not a collection of integer matrices generates a free group?
Sep 1 '11 at 6:00
13
Number of subgroups of a given index of a free group
Dec 2 '13 at 5:46
13
Walls of CAT(0) cube complex sufficiently far apart implies intersection of stabilizers finite
Dec 8 '12 at 18:11
13
Judging whether a finitely presented group is a 3-manifold group?
Oct 22 '12 at 9:38
13
Groups surjecting onto a free group
Nov 7 '11 at 10:17
13
When is a finitely generated group finitely presented?
Feb 10 '11 at 3:33
13
What can be said about a group from its presentation?
Aug 16 '10 at 14:46
12
A hyperbolic group with a small profinite completion
Jan 3 at 21:53
12
Virtual fibering conjecture for cusped hyperbolic manifolds
Feb 12 '14 at 22:08
12
What finitely presented groups embed into GL_2?
Jul 23 '12 at 19:55
12
Applications of the notion of of Gromov-Hausdorff distance
Feb 27 '11 at 13:15
12
Applications of infinite graph theory
Sep 22 '10 at 21:28
12
does every right-angled coxeter group have a right-angled artin group as a subgroup of finite index?
Mar 18 '10 at 17:12
11
HNN extensions which are free products
Dec 9 '09 at 16:23
11
Algorithms in hyperbolic groups
Apr 15 '14 at 20:43
MathOverflow works best with JavaScript enabled