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2-category 2-category-theory abelian-categories adjoint algebra algebraic algebraic-geometry algebraic-topology analysis analytic-geometry arithmetic arithmetic-geometry beauty bundles calculus categories category category-theory chern-weil-theory cohesion cohesive-homotopy-type-theory cohomology combinatorics complex-geometry computable-mathematics computer-science connection constructive cosmology definitions deformation-theory descent diagrams differential differential-cohomology differential-equations differential-geometry differential-topology digraphs duality elliptic-cohomology enriched fibration finite foundations functional-analysis functor galois-theory gauge-theory gebra geometric-quantization geometry graph graphs gravity grothendieck group-theory harmonic-analysis higher higher-algebra higher-category-theory higher-differential-geometry higher-geometry higher-lie-theory higher-topos-theory homological homological-algebra homotopy homotopy-theory homotopy-type-theory index-theory integration integration-theory internal-categories k-theory kan lie-theory limit limits linear linear-algebra locale localization logic manifolds mathematics measure-theory modal-logic model model-category-theory monoidal monoidal-category-theory morphism motives motivic-cohomology newpage nonassociative noncommutative noncommutative-geometry number-theory of operads operator operator-algebra order-theory pasting philosophy physics planar 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 stack string-theory subobject superalgebra supergeometry svg symplectic-geometry synthetic-differential-geometry terminology theory topology topos topos-theory tqft type type-theory universal variational-calculus

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- Discussion Type
- discussion topicNew stubs
- Category Latest Changes
- Started by TobyBartels
- Comments 4
- Last comment by TobyBartels
- Last Active Dec 16th 2009

Just look at the list of all wanted pages, here are a few stubby articles: 1-topos, 2-Hilbert space, Alexandroff compactification, Banach manifold. (Yes, I went alphabetically.)

- Discussion Type
- discussion topicNo more orphaned pages!
- Category Latest Changes
- Started by TobyBartels
- Comments 1
- Last comment by TobyBartels
- Last Active Dec 16th 2009

I have just made links to all of the contentful orphaned paged on the main nLab web. However, they may still be walled gardens; Instiki doesn't find those automatically.

In general, when you create a new page, it's a good idea to create a link to it from some existing page on a more general topic. (The links that I just made may not have been the best!) That way, it's more likely that people will actually find their way to your new page.

- Discussion Type
- discussion topicoo-Lie theory - contents
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Dec 16th 2009

I wanted to start expanding on the big story at nonabelian Lie algebra cohomology, but then found myself wanting to polish first a bit further the background material.

I came to think that it is about time to collect our stuff on "oo-Lie theory".

So I created a floating table of contents

and added it to most of the relevant entries.

This toc is based on the one on my personal web here -- but much larger now -- and still contains some links to my web, where I am trying to develop the full story. If anyone feels ill-at-ease with these links to my personal web, let me know.

- Discussion Type
- discussion topicstrict 2-group
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Dec 16th 2009

considerably expanded the entry strict 2-group.

Apart from adding an introductory discussion, and expanding the list of examples, in particular by adding that of automorphism 2-groups ...

... I in particular give the detailed translation prescription for how to encode a 2-group by a crossed module at In terms of crossed modules

This is to eventually serve as a supplement to the discussion at nonabelian group cohomology. So I spent some energy on disentangling the four different (though isomorphic) ways a crossed module gives rise to a 2-group (following my article with David Roberts).

- Discussion Type
- discussion topicRiemann surfaces and Myers-Steenrod theorem
- Category Latest Changes
- Started by amathew
- Comments 3
- Last comment by amathew
- Last Active Dec 15th 2009

I created [[Riemann surface]] and [[Myers-Steenrod theorem]].

- Discussion Type
- discussion topicstring Lie 2-algebra
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Dec 15th 2009

added the detailed definition to string Lie 2-algebra

- Discussion Type
- discussion topicNew page: [[classical mathematics]]
- Category Latest Changes
- Started by TobyBartels
- Comments 27
- Last comment by Urs
- Last Active Dec 15th 2009

I started classical mathematics to link to from internal logic.

- Discussion Type
- discussion topicframed bicategory
- Category Latest Changes
- Started by Urs
- Comments 2
- Last comment by TobyBartels
- Last Active Dec 13th 2009

created quick stub for framed bicategory

but my machine's battery will die any second now...

- Discussion Type
- discussion topicEdit conflict at [[model structure on dendroidal sets]]
- Category Latest Changes
- Started by TobyBartels
- Comments 4
- Last comment by TobyBartels
- Last Active Dec 11th 2009

It looked to me like Urs hit Ctrl-V instead of Ctrl-C there, so I rolled back, but now Urs is editing again, so probably he's just doing something that I interrupted. Since I can't leave a note there now, I'll leave one here: I won't interfere again, Urs.

- Discussion Type
- discussion topic(oo,1)-operads
- Category Latest Changes
- Started by Urs
- Comments 6
- Last comment by Urs
- Last Active Dec 11th 2009

added to (infinity,1)-operad the definition/proposition of the model structure for the category of (oo,1)-categories of operations here

- Discussion Type
- discussion topicObjections by Maarten
- Category Latest Changes
- Started by TobyBartels
- Comments 3
- Last comment by Urs
- Last Active Dec 10th 2009

Or possibly not by Maarten. Anyway, there is some discussion at superdifferential form and Weil algebra that people into that sort of thing should look at.

- Discussion Type
- discussion topicCategorification vs laxification
- Category Latest Changes
- Started by TobyBartels
- Comments 20
- Last comment by TobyBartels
- Last Active Dec 10th 2009

I added to vertical categorification the comments that I'd made at MathOverflow, as Urs has requested. I'm not sure that I'm happy with where I put them and how I labelled them, but maybe it's better if other people judge that.

- Discussion Type
- discussion topichomotopy coinvariants
- Category Latest Changes
- Started by zskoda
- Comments 1
- Last comment by zskoda
- Last Active Dec 10th 2009

New item homotopy coinvariants functor, after a paper of Kathryn Hess. For now just a definition.

- Discussion Type
- discussion topicPresenting categories with large simplicial sets
- Category Latest Changes
- Started by TobyBartels
- Comments 2
- Last comment by Harry Gindi
- Last Active Dec 10th 2009

More discussion about this at category theory.

- Discussion Type
- discussion topicGavin Wraith wrote [[geometric theory]].
- Category Latest Changes
- Started by TobyBartels
- Comments 1
- Last comment by TobyBartels
- Last Active Dec 9th 2009

Gavin Wraith wrote geometric theory.

- Discussion Type
- discussion topicEvil composition
- Category Latest Changes
- Started by Harry Gindi
- Comments 2
- Last comment by Andrew Stacey
- Last Active Dec 9th 2009

- Discussion Type
- discussion topicTypes of shapes of limit cones
- Category Latest Changes
- Started by domenico_fiorenza
- Comments 5
- Last comment by TobyBartels
- Last Active Dec 9th 2009

- I'd like to add the following "shape" to http://ncatlab.org/nlab/show/limit#types_of_shapes_of_limit_cones_17 :

The limit of the identity functor Id: C --> C is the initial object of C (it it exists).

- Discussion Type
- discussion topicPersonal web updated
- Category Latest Changes
- Started by Guest
- Comments 7
- Last comment by Guest
- Last Active Dec 9th 2009

- I've added the latest, almost complete, draft of my thesis to my personal web - go via David Roberts. Comments on introduction are welcome, if you feel so inclined. Just put them on David Roberts.

On a related note, is it quite legitimate to post updates on personal webs here? (Now that I've already done it)

David Roberts

- Discussion Type
- discussion topicEckmann-Hilton duality
- Category Latest Changes
- Started by zskoda
- Comments 11
- Last comment by zskoda
- Last Active Dec 8th 2009

New entry Eckmann-Hilton duality. Discussion welcome.

- Discussion Type
- discussion topicTrimble n-category
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Dec 8th 2009

I edited Trimble n-category:

added table of contents

added hyperlinks

moved the query boxes that seemed to contain closed discussion to the bottom. I kept the query box where I ask for a section about category theory for Trimble n-categories, but maybe we want to remove that, too. Todd has more on this on his personal web.

- Discussion Type
- discussion topicCategory theory
- Category Latest Changes
- Started by Guest
- Comments 3
- Last comment by TobyBartels
- Last Active Dec 7th 2009

- Edited the page category theory. Mostly about that certain presheaves are the same as categories and the long discussion at the end with an idea how to solve my problem about CW-complexes. Removed precursors link since there is nothing about them in nLab. This new logging is a bit confusing and harder to read.

-Rafael

- Discussion Type
- discussion topicEk-Algebras
- Category Latest Changes
- Started by Urs
- Comments 7
- Last comment by zskoda
- Last Active Dec 7th 2009

started extracting stuff from Ek-Algebras

added the statement of the main result and created a new subsection at k-tuply monoidal n-category to link to it

renamed the previous entry E-k operad into little cubes operad

- Discussion Type
- discussion topicuniversal algebra in a monoidal category
- Category Latest Changes
- Started by Andrew Stacey
- Comments 35
- Last comment by Andrew Stacey
- Last Active Dec 7th 2009

Created universal algebra in a monoidal category

In the lab book metaphor, this page is some jottings of stuff that I'm pretty sure must be out there (as it's a fairly obvious thing to do) but have no idea of what it's called (hedgehogs, perhaps?). So I'd be grateful if someone strong in the ways of Lawvere theories could stop by and help me out.

(Plus I had to make up the notation and terminology as I went along so that's all horrible)

Hopefully the big box at the top of the page makes this clear!

- Discussion Type
- discussion topicdouble bicategory
- Category Latest Changes
- Started by John Baez
- Comments 5
- Last comment by John Baez
- Last Active Dec 7th 2009

- I started a little page called double bicategory.

- Discussion Type
- discussion topicDefinition of extended TQFT
- Category Latest Changes
- Started by domenico_fiorenza
- Comments 6
- Last comment by domenico_fiorenza
- Last Active Dec 5th 2009

- I apologize in case this discussion is already open and I have been unable to find it.

There is something I am unable to undrstand in the definition of extended TQFT as on the nLab page http://ncatlab.org/nlab/show/extended+topological+quantum+field+theory

Namely, it seems to me that the recursive definition should rather end with "smooth compact oriented (n-m+1)-manifolds to R-linear (m?2)-categories"

- Discussion Type
- discussion topicLong time lurker, first time writer
- Category Latest Changes
- Started by TobyBartels
- Comments 1
- Last comment by TobyBartels
- Last Active Dec 5th 2009

One of these has started (or continued) a conversation at the bottom of graph.

- Discussion Type
- discussion topicferrim
- Category Latest Changes
- Started by Andrew Stacey
- Comments 9
- Last comment by Andrew Stacey
- Last Active Dec 4th 2009

I'm guessing that ferrim is spam. If no-one says anything to the contrary within 24hrs then I'll add it to the spam category.

If it is spam, it's either a random spambot post or it's someone testing to see how vigilant we are. If the latter, as there's no content then they may simply test to see if the link stays active. In which case, our previous "policy" of blanking the content won't send the right signal here (especially as there's no content to blank). Is there any objection to renaming spam entries? Say, as 'spam (original title)' (or whatever the allowable punctuation characters are)?

- Discussion Type
- discussion topicNormal monomorphisms between dendroidal sets.
- Category Latest Changes
- Started by TobyBartels
- Comments 3
- Last comment by TobyBartels
- Last Active Dec 4th 2009

I asked a question at dendroidal set and wrote normal monomorphism to explain it.

- Discussion Type
- discussion topicsymmetric spectra
- Category Latest Changes
- Started by Urs
- Comments 1
- Last comment by Urs
- Last Active Dec 4th 2009

added to symmetric monoidal smash product of spectra a link to a pdf with seminar notes that nicely recall the definition of the symmetric monoidal category of spectra.

- Discussion Type
- discussion topicH-space
- Category Latest Changes
- Started by zskoda
- Comments 1
- Last comment by zskoda
- Last Active Dec 4th 2009

In entry groupoid object in an (infinity,1)-category there is a passage

"it is the generalization of Stasheff H-space from Top to more general ?-stack (?,1)-topoi: an object that comes equipped with an associative and invertible monoid structure, up to coherent homotopy"

I repeat what I documented in earlier discussion on H-space: H-spaces are widely used terminology since 1950, thus before Stasheff work which of course is an important work on coherencies for them. So it is likely improper to say Stasheff H-space...Stasheff has REFINEMENTS of H-spaces, namely $A_n$-spaces and the group-like case is A infty spaces.