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    • 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.

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