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

Site Tag Cloud

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

• CommentRowNumber1.
• CommentAuthorUrs
• CommentTimeMay 12th 2011
• (edited Nov 28th 2011)

started Yetter model, still a stub so far. Tim, I trust you will add references?! :-)

• CommentRowNumber2.
• CommentAuthorTim_Porter
• CommentTimeMay 13th 2011

I know the Yetter model as such (with a non-discrete 2-group) but that is more recent. I will see what could be added here, but will need to cross check to other possible entries. Is it :

[CY] Crane, L. and Yetter, D.N., “A Categorical Construction of 4D Topological Quantum Field Theories,” in Quantum Topology, Kau

• CommentRowNumber3.
• CommentAuthorUrs
• CommentTimeMay 13th 2011

Hi Tim,

I was thinking of

• David Yetter, TQFTs from homotopy 2-types , Journal of Knot Theory and its Ramifications 2 (1993), 113-123.

• João Faria Martins Tim Porter, On Yetter’s invariants and an extension of the Dijkgraaf-Witten invariant to categorical groups (TAC)

but now I see I should just have said “Yetter model”, not Crane-Yetter. Sorry. I have renamed the entry to Yetter model.

• CommentRowNumber4.
• CommentAuthorTim_Porter
• CommentTimeMay 15th 2011

Ah! That explains it. I think I know two other references…. so will add them, giving another example of blatant self advertisement on the web.

• CommentRowNumber5.
• CommentAuthorUrs
• CommentTimeNov 28th 2011
• (edited Nov 28th 2011)

I have added to the references at Yetter model the article by Marco Mackay.

Mackay mentions 4-cocycles, but uses them just on a 1-group. Other references that do consider the Yetter model for genuine 2-groups seem to either consider no cocycles or just 3-cocycles.

Is there any references that explicitly talks about the Yetter model for a genuine target 2-type with a non-trivial 4-cocycle on it?

• CommentRowNumber6.
• CommentAuthorUrs
• CommentTimeOct 7th 2013
• (edited Oct 7th 2013)

I have cross-linked Yetter model with Turaev-Viro model citing the theorem by Barrett et al that shows that the latter is the boundary theory of the former.

Thanks to Bruce Bartlett for the pointer!

• CommentRowNumber7.
• CommentAuthorxgwen
• CommentTimeOct 11th 2013
I maybe wrong on this, but I thought the Turaev-Viro model is a 3d TQFT construction induced from a fusion category (not from modular tensor category). The Turaev-Viro model from from fusion category is more general.
• CommentRowNumber8.
• CommentAuthorUrs
• CommentTimeOct 11th 2013

Thanks for catching this. I have now edited the intro (still brief) at Turaev-Viro model a bit more.

• 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)