Not signed in (Sign In)

Start a new discussion

Not signed in

Want to take part in these discussions? Sign in if you have an account, or apply for one below

  • Sign in using OpenID

Site Tag Cloud

2-category 2-category-theory abelian-categories adjoint algebra algebraic algebraic-geometry algebraic-topology analysis analytic-geometry arithmetic arithmetic-geometry book bundles calculus categorical categories category category-theory chern-weil-theory cohesion cohesive-homotopy-type-theory cohomology colimits combinatorics complex-geometry computable-mathematics computer-science constructive cosmology deformation-theory descent diagrams differential differential-cohomology differential-equations differential-geometry differential-topology digraphs duality elliptic-cohomology enriched fibration finite foundations functional-analysis functor gauge-theory gebra geometric-quantization geometry goodwillie-calculus graph graphs gravity grothendieck group group-theory harmonic-analysis higher higher-algebra higher-category-theory higher-differential-geometry higher-geometry higher-lie-theory higher-topos-theory homological homological-algebra homology homotopy homotopy-theory homotopy-type-theory index-theory integration integration-theory k-theory lie-theory limits linear linear-algebra locale localization logic mathematics measure-theory modal modal-logic model model-category-theory monads monoidal monoidal-category-theory morphism motives motivic-cohomology newpage nforum nlab noncommutative noncommutative-geometry number-theory object of operads operator operator-algebra order-theory pages pasting philosophy physics pro-object probability probability-theory quantization quantum quantum-field quantum-field-theory quantum-mechanics quantum-physics quantum-theory question representation representation-theory riemannian-geometry scheme schemes set set-theory sheaf simplicial space spin-geometry stable-homotopy-theory string string-theory superalgebra supergeometry svg symplectic-geometry synthetic-differential-geometry terminology theory topology topos topos-theory type type-theory universal variational-calculus

Vanilla 1.1.10 is a product of Lussumo. More Information: Documentation, Community Support.

Welcome to nForum
If you want to take part in these discussions either sign in now (if you have an account), apply for one now (if you don't).
    • CommentRowNumber1.
    • CommentAuthorTim_Porter
    • CommentTimeMar 5th 2010

    I have started an entry on proper homotopy theory. This is partially since it will be needed in discussing some parts of strong shape theory, but it may also be useful for discussing duality and various other topics, including studying non-compact spaces in physical contexts. This is especially true for non-compact manifolds. (I do not know what fibre bundles etc. look like in the proper homotopy setting!)

    • CommentRowNumber2.
    • CommentAuthorTim_Porter
    • CommentTimeMar 7th 2010

    I have added more material here. So far I have defined the proper homotopy category, and have started discussing ends. (not categorical ones, topological ones).

    • CommentRowNumber3.
    • CommentAuthorTim_Porter
    • CommentTimeMar 8th 2010

    I have put a query box about the space of ends as a maximal ideal space of some ring. Thought I should draw attention to it, as I am at a loss to see the analogue between the proper theory here and analogues in algebraic geometry. Anyone any ideas?

    • CommentRowNumber4.
    • CommentAuthorDavidRoberts
    • CommentTimeNov 10th 2010

    Question at proper homotopy theory about a typo I can’t fix.

    • CommentRowNumber5.
    • CommentAuthorTim_Porter
    • CommentTimeNov 10th 2010

    @David. I can’t figure out what your question is? Doh!

    A subspace A in X is cofinal if its complement is sort of compact, but as we want allow for A to be closed in X we take the closure of the complement cl(X-A). Am I reading what I want rather than what I wrote, somehow?

    • CommentRowNumber6.
    • CommentAuthorDavidRoberts
    • CommentTimeNov 10th 2010

    That’s it, I think. There was a WW which should have been an XX, I think. I sort of figured it out afterwards, but I wanted to be sure.

    • CommentRowNumber7.
    • CommentAuthorDavidRoberts
    • CommentTimeNov 10th 2010

    I’ve edited the page and removed my comment.

    • CommentRowNumber8.
    • CommentAuthorTim_Porter
    • CommentTimeNov 10th 2010

    I wanted X so I read X. Here I have just got up and I forgot to switch my eyes on!!!!!!! Double doh!

    • CommentRowNumber9.
    • CommentAuthorTim_Porter
    • CommentTimeNov 13th 2010

    I have created an entry on the Brown-Grossman homotopy groups. This contains (will contain once I have typed it!) a statement of the Whitehead theorem in this setting. This gives neat conditions globally and at the ends for a map to be a proper homotopy equivalence.

    • CommentRowNumber10.
    • CommentAuthorTim_Porter
    • CommentTimeAug 22nd 2011
    • (edited Aug 22nd 2011)

    Igor Khavkine has recreated the entry Proper Homotopy Theory. The old copy gave an error message, (Application error (Apache)

    Something very bad just happened. I just know it. Do you smell smoke?) I would rename his copy to be the main one but I don’t recall how to do this, and it would be good to know what went wrong with the old page.

    • CommentRowNumber11.
    • CommentAuthorAndrew Stacey
    • CommentTimeAug 22nd 2011

    What went wrong was the last two lines:

    Lecture Notes:
    *   D. A. Edwards and H. M. Hastings, _Čech and Steenrod Homotopy Theory with Applications,_ SLNM 542, Springer (1976).

    That final * confused Maruku as it was expecting a list item but got the end of the page. The smoke error was probably a bit drastic, though! (I’ve reported this to Jacques).

    For “old hands”, it’s useful to know that even if the show method is causing smoke, it’s still possible to manually get to the edit or source views simply by editing the URL. Sometimes there’s something really obviously wrong and changing it fixes the problem.

    • CommentRowNumber12.
    • CommentAuthorAndrew Stacey
    • CommentTimeAug 22nd 2011

    I see that Igor had also fixed a couple of wikilinks, so I’ve copied his version to proper homotopy theory, and I’ll blank (or almost blank) the new one and rename it to proper homotopy theory > history.

    • CommentRowNumber13.
    • CommentAuthorAndrew Stacey
    • CommentTimeAug 22nd 2011

    Incidentally, I don’t know why it suddenly started causing the bug. I do know that Jacques has been working on the maruku rendering engine to speed it up a little bit, so presumably it sneaked in there.

Add your comments
  • Please log in or leave your comment as a "guest post". If commenting as a "guest", please include your name in the message as a courtesy. Note: only certain categories allow guest posts.
  • To produce a hyperlink to an nLab entry, simply put double square brackets around its name, e.g. [[category]]. To use (La)TeX mathematics in your post, make sure Markdown+Itex is selected below and put your mathematics between dollar signs as usual. Only a subset of the usual TeX math commands are accepted: see here for a list.

  • (Help)