User Roberto Frigerio - MathOverflow

Roberto Frigerio

Member for 13 years, 6 months
Last seen more than a month ago

dm.unipi.it/~frigerio
Pisa, Italy

22 Answers

Score Activity Newest

21 votes

Accepted

How many elements does it take to normally generate a group?

answered Feb 10, 2011 at 0:24

18 votes

Accepted

Non-commutator in simple group?

answered May 1, 2012 at 21:22

14 votes

Accepted

Which knots are singularities of a hyperbolic cone-manifold structures on $S^3$?

answered Oct 10, 2018 at 13:16

13 votes

Connections between ultrafilters in topology and logic

answered May 27, 2010 at 15:26

10 votes

Do you know how to construct a compact hyperbolic 3-manifold with three or four totally geodesic boundary components?

answered May 20, 2010 at 13:21

10 votes

When does Cantor-Bernstein hold?

answered Aug 21, 2011 at 14:53

9 votes

Example of a manifold which is not a homogeneous space of any Lie group

answered Feb 24, 2012 at 0:29

9 votes

The number of cusps of higher-dimensional hyperbolic manifolds

answered Mar 26, 2013 at 12:26

9 votes

Accepted

Isometries between metric spaces

answered Aug 21, 2011 at 14:43

9 votes

Can anyone give me a good example of two interestingly different ordinary cohomology theories?

answered May 31, 2010 at 14:10

9 votes

Is there a finitely additive measure on R which is not sigma-additive?

answered Oct 19, 2018 at 10:36

8 votes

Is there a combinatorial analogue of Ricci flow?

answered May 22, 2011 at 12:21

7 votes

Accepted

Is the cut locus of a generic point in a hyperbolic manifold a generic polyhedron?

answered Oct 28, 2010 at 9:01

6 votes

A name for a weak topology

answered Apr 24, 2012 at 16:13

6 votes

center of fundamental group of finite volume-hyperbolic orbifold

answered Jan 14, 2012 at 16:34

5 votes

Uniquely geodesic and CAT(0) spaces?

answered Aug 31, 2013 at 11:54

5 votes

When does a homomorphism factor through a free group?

answered Jul 29, 2012 at 19:56

4 votes

Accepted

Does Dehn filling always decrease Gromov norm?

answered Sep 26, 2013 at 13:05

4 votes

Is there a quaternionic algebraic geometry ?

answered Jan 14, 2011 at 11:55

3 votes

fundamental groups of surfaces

answered Jun 19, 2011 at 12:59

3 votes

Is there a "knot theory" for graphs?

answered Oct 31, 2011 at 21:08

1 vote

Can the fundamental group of an intersection of a homeomorphic image of a ball with a complement of a ball in $R^3$ be perfect?

answered Aug 27, 2012 at 23:20