Andy Putman's user avatar
Andy Putman's user avatar
Andy Putman's user avatar
Andy Putman
  • Member for 14 years, 5 months
  • Last seen this week
19 votes
Accepted

Non-split extensions of $GL_n(F_q)$ by $F_q^n$ ?

19 votes
Accepted

Cohomology of fibrations over the circle

19 votes
Accepted

Distinguishing congruence subgroups of the modular group

18 votes

Why are free groups residually finite?

18 votes
Accepted

Differentiable structures on R^3

18 votes
Accepted

Are mapping class groups of orientable surfaces good in the sense of Serre?

18 votes
Accepted

Extension of the Hall-Witt identity

18 votes

Stably equivalent but not homotopy equivalent

18 votes
Accepted

Is there an algorithm to decide if a word is in a finitely generated subgroup of a free group?

17 votes
Accepted

Foliation of $\mathbb R^n$ by connected compact manifolds

17 votes
Accepted

Is there a Riemannian metric on the configuration space of $n$ distinct points with "nice" geodesics?

17 votes
Accepted

Existence of sections of the evaluation map for the diffeomorphism group

17 votes
Accepted

Picard Groups of Moduli Problems

17 votes
Accepted

Homotopy type of the plane minus a sequence with no limit points

17 votes

Cohomology of fibrations over the circle

16 votes

What are the advantages and disadvantages of the Moore method?

16 votes

Essential theorems in group (co)homology

16 votes

understanding Steenrod squares

16 votes
Accepted

Signatures on the infinite symmetric group

16 votes

Compactification theorem for differentiable manifolds ?

16 votes

Are nets and filters useful in geometry and topology?

16 votes

Beyond an intro to topological graph theory...

16 votes
Accepted

When are growth series rational?

16 votes
Accepted

Cohomology of braid groups with coefficients in the group ring

16 votes
Accepted

Who proved that two homotopic embeddings of one surface in another are isotopic?

16 votes
Accepted

Does this subgroup of "even braids" have a name?

16 votes
Accepted

Generators for the first cohomology of free groups

16 votes
Accepted

Can automorphism equivalence in a free group be detected in a nilpotent quotient?

15 votes

Cohomology of quotient by free action

15 votes

Extending a diffeomorphism of the sphere $S^2$ to the ball $D^3$

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