Skip to main content
Search type Search syntax
Tags [tag]
Exact "words here"
Author user:1234
user:me (yours)
Score score:3 (3+)
score:0 (none)
Answers answers:3 (3+)
answers:0 (none)
isaccepted:yes
hasaccepted:no
inquestion:1234
Views views:250
Code code:"if (foo != bar)"
Sections title:apples
body:"apples oranges"
URL url:"*.example.com"
Saves in:saves
Status closed:yes
duplicate:no
migrated:no
wiki:no
Types is:question
is:answer
Exclude -[tag]
-apples
For more details on advanced search visit our help page
Results tagged with
Search options not deleted user 1291

Homotopy theory, homological algebra, algebraic treatments of manifolds.

14 votes

Examples of non Quillen-equivalent model categories having equivalent homotopy categories

Daniel Dugger and Brooke Shipley give an example in their paper A curious example of triangulated-equivalent model categories which are not Quillen equivalent available here.
Rasmus's user avatar
  • 3,174
5 votes
2 answers
448 views

What is the group of additive operations on topological K-theory?

Let us view topological K-theory as a functor $K$ from the cateory of compact pairs (that is, a compact Hausdorff spaces with a distinguished closed subset) to the category of $\mathbb Z/2$-graded Abe …
Rasmus's user avatar
  • 3,174
6 votes
0 answers
367 views

Does every exact six-term sequence arise as the K-theory of a locally compact pair?

Consider six countable Abelian groups and six group homomorphims as in the following diagram G → H → I ↑ ↓ L ← K ← J Assume that the resulting sequence is exact at all six entries. Question …
Rasmus's user avatar
  • 3,174
2 votes
2 answers
1k views

Proving homotopy invariance of cellular homology by constructing a chain homotopy

I'm trying to follow an argument in Lück's "Algebraische Topologie: Homologie und Mannigfaltigkeiten" (to which there apparently doesn't exist an english translation). The aim is to check homotopy inv …
Rasmus's user avatar
  • 3,174
4 votes

Adams Spectral Sequence for Triangulated Categories

A general treatment of the Adams spectral sequence in the context of triangulated categories based on the work of Brinkmann and Christensen can be found here: http://arxiv.org/pdf/0801.1344. No monoi …
Rasmus's user avatar
  • 3,174
5 votes
2 answers
2k views

Homotopy limit-colimit diagrams in stable model categories

It is shown in Remark 7.1.12 of (a newer version of) Mark Hovey's book Model Categories that, in a stable model category, homotopy pullback squares coincide with homotopy pushout squares. The argument …
Rasmus's user avatar
  • 3,174
9 votes

Non-examples of model structures, that fail for subtle/surprising reasons?

By a result of Schochet, the category of C*-algebras with homotopy equivalences and "Schochet fibrations" is a pointed category of fibrant objects whose homotopy category is the ordinary homotopy cate …
Rasmus's user avatar
  • 3,174