User Jeff Strom

38 votes

2 answers

2k views

Finite complexes whose homotopy groups are not "finitely generated"

asked May 29, 2014 at 1:32

25 votes

1 answer

3k views

Bouncing a ball down the stairs

asked Jun 19, 2014 at 0:59

19 votes

4 answers

2k views

Difference between represented and singular cohomology?

asked Jun 24, 2010 at 20:28

19 votes

1 answer

2k views

Slick Proof of Kudo Transgression Theorem

asked Mar 11, 2011 at 1:27

15 votes

2 answers

973 views

Pointed Hurewicz model structure

asked Nov 30, 2010 at 4:29

14 votes

5 answers

2k views

Good reference for homology of $K(\mathbb{Z}, 2n)$?

asked Jun 7, 2010 at 16:56

13 votes

2 answers

3k views

Left and right eigenvalues

asked Jul 17, 2010 at 17:13

13 votes

2 answers

2k views

Quasifibrations and homotopy pullbacks

asked Jan 30, 2011 at 14:23

12 votes

0 answers

661 views

Mapping cylinders of fibrations

asked Dec 15, 2010 at 14:46

12 votes

2 answers

647 views

Spaces that invert weak homotopy equivalences.

asked Nov 23, 2010 at 2:15

12 votes

1 answer

748 views

Open subspaces of CW complexes

asked Aug 26, 2019 at 15:11

10 votes

2 answers

741 views

Model categories of simplicial objects

asked Jan 12, 2011 at 18:46

9 votes

1 answer

1k views

Are there homotopy equivalences that are not weak homotopy equivalences?

asked Jul 15, 2010 at 19:22

9 votes

1 answer

298 views

Retracting a wedge of spheres off a homotopy fiber

asked Feb 10, 2018 at 17:12

9 votes

0 answers

393 views

When is an increasing union a colimit?

asked Jul 29, 2020 at 15:53

8 votes

1 answer

273 views

Pointed versus unpointed maps into a topological monoid

asked Mar 12, 2021 at 14:15

8 votes

1 answer

610 views

Pushouts and products in categories

asked Sep 11, 2020 at 14:35

8 votes

1 answer

220 views

Splitting low-dimensional $p$-local CW complexes for large $p$

asked Jun 14, 2019 at 14:38

8 votes

2 answers

2k views

Splitting of the Universal Coefficients sequence

asked Jun 13, 2010 at 1:26

8 votes

3 answers

535 views

Order of the identity map of a Moore space.

asked Nov 19, 2010 at 3:01

7 votes

1 answer

206 views

Injectivity of Rewrite Rule in a Free Lie Algebra

asked Nov 21, 2014 at 20:45

7 votes

0 answers

112 views

Stable splitting of products

asked Aug 1, 2019 at 13:29

7 votes

1 answer

200 views

Quasifibrations and transfinite filtrations

asked May 21, 2021 at 21:16

6 votes

2 answers

179 views

Nonhomeomophic spaces with homeomorphic mapping cones

asked Aug 26, 2020 at 0:22

6 votes

1 answer

1k views

Solid rings and Tor

asked Apr 25, 2012 at 13:57

6 votes

0 answers

284 views

Reference request: splittings in rational homotopy theory

asked May 4, 2012 at 2:00

6 votes

0 answers

78 views

Examples of maps with nontrivial Hopf invariant but Lusternik-Schnirelmann category of the cofiber doesn't increase?

asked Jun 24, 2016 at 13:47

6 votes

0 answers

226 views

Joins and classifying spaces in the category of compactly generated spaces

asked Jan 15, 2011 at 17:12

6 votes

3 answers

3k views

The fiber of a Serre fibration

asked Jan 29, 2011 at 17:41

6 votes

0 answers

510 views

The Mapping Cylinder of a Pullback Square

asked Sep 22, 2010 at 14:48

Stack Exchange Network

66 Questions

Finite complexes whose homotopy groups are not "finitely generated"

Bouncing a ball down the stairs

Difference between represented and singular cohomology?

Slick Proof of Kudo Transgression Theorem

Pointed Hurewicz model structure

Good reference for homology of $K(\mathbb{Z}, 2n)$?

Left and right eigenvalues

Quasifibrations and homotopy pullbacks

Mapping cylinders of fibrations

Spaces that invert weak homotopy equivalences.

Open subspaces of CW complexes

Model categories of simplicial objects

Are there homotopy equivalences that are not weak homotopy equivalences?

Retracting a wedge of spheres off a homotopy fiber

When is an increasing union a colimit?

Pointed versus unpointed maps into a topological monoid

Pushouts and products in categories

Splitting low-dimensional $p$-local CW complexes for large $p$

Splitting of the Universal Coefficients sequence

Order of the identity map of a Moore space.

Injectivity of Rewrite Rule in a Free Lie Algebra

Stable splitting of products

Quasifibrations and transfinite filtrations

Nonhomeomophic spaces with homeomorphic mapping cones

Solid rings and Tor

Reference request: splittings in rational homotopy theory

Examples of maps with nontrivial Hopf invariant but Lusternik-Schnirelmann category of the cofiber doesn't increase?

Joins and classifying spaces in the category of compactly generated spaces

The fiber of a Serre fibration

The Mapping Cylinder of a Pullback Square