User IJL

27 votes

The use of computers leading to major mathematical advances II

answered Jul 1, 2021 at 9:02

14 votes

Accepted

Translation lengths in CAT(0) spaces

answered Mar 5, 2021 at 16:45

12 votes

Accepted

Quotient of solid torus by swapping coordinates on boundary

answered Dec 22, 2021 at 16:46

11 votes

Accepted

Non-finitely presented FP groups with cohomological dimension $2$

answered Feb 14, 2022 at 10:14

11 votes

Accepted

Not very transitive actions

answered Nov 10, 2022 at 17:21

10 votes

Accepted

Finite domination and Poincaré duality spaces

answered Oct 5, 2022 at 9:15

9 votes

Accepted

Why is the number of Hamiltonian Cycles of n-octahedron equivalent to the number of Perfect Matching in specific family of Graphs?

answered Jun 12, 2018 at 16:21

9 votes

Mistakes in Bredon's book "Topology and Geometry"?

answered Jan 25, 2019 at 11:59

9 votes

How many non-isomorphic extensions with kernel $S^1$ and quotient cyclic of order $p$?

answered Apr 30, 2019 at 13:32

8 votes

Spheres in simplicial complexes with homotopy type of a wedge of spheres

answered May 2, 2018 at 15:34

8 votes

(co)homology of symmetric groups

answered May 22, 2018 at 17:08

8 votes

Cohomology of simple finite groups remembers the group?

answered Apr 22, 2019 at 18:12

8 votes

Accepted

Status of the Hopf-Thurston sign conjecture in dimension 4

answered Feb 13, 2022 at 16:06

7 votes

Perfect group that is split extension of a normal free subgroup of finite index

answered May 23, 2022 at 14:58

7 votes

Accepted

Higher order differentials of Bockstein spectral sequence

answered Jun 23, 2022 at 10:24

6 votes

Is there a contractible hyperbolic 3-orbifold of finite volume?

answered Nov 28, 2022 at 16:04

6 votes

Accepted

Computation of cohomology of Morava $K$-Theory

answered Apr 21, 2022 at 9:47

6 votes

Accepted

Groups with unusual cohomological dimension of direct product

answered Mar 12, 2022 at 13:03

6 votes

Cover the $n$-disc irredundantly with $n+1$ open sets. Suppose that the $(n+1)$-fold intersection is empty. Then is some $n$-fold intersection empty?

answered Apr 14 at 20:06

6 votes

Accepted

Is the dimension given by Klee trick ever sharp?

answered Jan 16, 2019 at 15:42

6 votes

Is there a finitely presented group with infinite homology over $\mathbb{Q}$?

answered Oct 9, 2020 at 17:43

6 votes

How many finitely-generated-by-elements-of-finite-order-groups are there?

answered Apr 16, 2021 at 11:48

6 votes

Small simplicial set models for BG

answered Jul 26, 2021 at 15:52

6 votes

Accepted

can the actions of fundamental groups annihilate homology?

answered Nov 19, 2020 at 16:15

6 votes

Finite complexes whose homotopy groups are not "finitely generated"

answered May 21, 2018 at 16:37

6 votes

Accepted

Cohomology of $\mathbb Z_4$ via the Lyndon-Hochschild-Serre spectral sequence

answered Aug 23, 2018 at 16:08

5 votes

Topological interpretation for groups of type $FP_2$

answered Jun 13, 2018 at 11:52

5 votes

Geometric dissection theory

answered May 20, 2019 at 15:13

5 votes

Can a cyclic group of prime order act on a rationally acyclic finite dimensional complex and have no fixed points?

answered Jan 7, 2023 at 18:02

5 votes

Accepted

Iterated algebraic fibering

answered Oct 3, 2022 at 9:05

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60 Answers

The use of computers leading to major mathematical advances II

Translation lengths in CAT(0) spaces

Quotient of solid torus by swapping coordinates on boundary

Non-finitely presented FP groups with cohomological dimension $2$

Not very transitive actions

Finite domination and Poincaré duality spaces

Why is the number of Hamiltonian Cycles of n-octahedron equivalent to the number of Perfect Matching in specific family of Graphs?

Mistakes in Bredon's book "Topology and Geometry"?

How many non-isomorphic extensions with kernel $S^1$ and quotient cyclic of order $p$?

Spheres in simplicial complexes with homotopy type of a wedge of spheres

(co)homology of symmetric groups

Cohomology of simple finite groups remembers the group?

Status of the Hopf-Thurston sign conjecture in dimension 4

Perfect group that is split extension of a normal free subgroup of finite index

Higher order differentials of Bockstein spectral sequence

Is there a contractible hyperbolic 3-orbifold of finite volume?

Computation of cohomology of Morava $K$-Theory

Groups with unusual cohomological dimension of direct product

Cover the $n$-disc irredundantly with $n+1$ open sets. Suppose that the $(n+1)$-fold intersection is empty. Then is some $n$-fold intersection empty?

Is the dimension given by Klee trick ever sharp?

Is there a finitely presented group with infinite homology over $\mathbb{Q}$?

How many finitely-generated-by-elements-of-finite-order-groups are there?

Small simplicial set models for BG

can the actions of fundamental groups annihilate homology?

Finite complexes whose homotopy groups are not "finitely generated"

Cohomology of $\mathbb Z_4$ via the Lyndon-Hochschild-Serre spectral sequence

Topological interpretation for groups of type $FP_2$

Geometric dissection theory

Can a cyclic group of prime order act on a rationally acyclic finite dimensional complex and have no fixed points?

Iterated algebraic fibering