Not signed in (Sign In)

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

Discussion Tag Cloud

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.
    • CommentAuthorUrs
    • CommentTimeDec 23rd 2015

    I have started a category:reference page

    such as to be able to point to it for reference, e.g. from Kontsevich 15 etc.

    • CommentRowNumber2.
    • CommentAuthorDavid_Corfield
    • CommentTimeFeb 28th 2018

    Damien Calaque’s contribution has just appeared, so I’ve added a link.

    • CommentRowNumber3.
    • CommentAuthorDavid_Corfield
    • CommentTimeFeb 28th 2018

    It says there about dcct and other articles:

    Observe that these references also deal with variants of shifted pre-symplectic structures on stacks, but the non-degeneracy condition is almost never satisfied as everything takes place in the realm of underived stacks.

    I was reminded of our conversation here.

    By the way, the talk slides link at Prequantum field theories from Shifted symplectic structures doesn’t work.

    • CommentRowNumber4.
    • CommentAuthorDavid_Corfield
    • CommentTimeFeb 28th 2018
    • (edited Mar 1st 2018)

    Anel’s paper added too.

    Good final flourish to the paper!

    • CommentRowNumber5.
    • CommentAuthorUrs
    • CommentTimeMar 1st 2018
    • (edited Mar 2nd 2018)

    Thanks for the alerts. I have fixed that link.

    It says there about dcct and other articles:

    Observe that these references also deal with variants of shifted pre-symplectic structures on stacks, but the non-degeneracy condition is almost never satisfied as everything takes place in the realm of underived stacks.

    It is noteworthy that non-degenerate symplectic structure in gauge field theory is all about recitifying a homotopy-theoretic structure: the gauge-fixing of the BV-BRST complex which ensures the non-degenerate graded symplectic structure is a means to quantize homotopy-theoretically by doing it naively but degreewise, respecting a differential (chapter 11). This is in direct analogy to how a naive Lie algebra considered degreewise and respecting a differential (hence a dg-Lie algebra) is a rigidified model for a strong homotopy Lie algebra.

    While it is true that presently this homotopy-rigidified trick is the only known way to quantize gauge field theory, in general, it is clear from the point of view of homotopy theory that this must be but a tool and a convenience, not a fundamental necessity. It ought to be true that there is a homotpy-quantization procedure which reads in the non-gauge fixed and hence degenerate presymplectic current (aka shifted pre-symplectic structure) and quantizes it right away.

    This is ultimately what Marco Benini and Alexander Schenkel are headed for in their homotopical AQFT. Their toy example of free electromagnetism sort of works this way already, but there is a long way to go until this will be understood generally. Meanwhile, it is good to have a clear picture of the role that symplectic rather than pre-symplectic structure plays in QFT.

    • CommentRowNumber6.
    • CommentAuthorDavid_Corfield
    • CommentTimeMar 1st 2018

    So a way needs to be found to realise

    quantization is the result of forming the homotopy quotient of the space of Lagrangian data by these duality relations?

    • CommentRowNumber7.
    • CommentAuthorUrs
    • CommentTimeMar 2nd 2018
    • (edited Mar 2nd 2018)

    That sounds possibly circular, since how would one know about duality relations without first having an independent construction of quantization in the first place. But who knows what the future will bring.

    But the point under discussion above is a different one: The Lagrangian densities that define Lagrangian field theory (up to renormalization choices) a priori yield higher pre-symplectic structure, not higher symplectic structure. The latter is obtained only after auxiliary fields are adjoined and a choice of BV-gauge fixing is made, which is directly analogous to choosing a differential graded algebra over an operad as a rectified model for an \infty-algebra over an \infty -operad. It works and is often convenient, sometimes it may even be the only tool under control, but it is not part of the definition of the homotopy theoretic concept.

    That’s why I always thought it pays to have a thorough look at higher pre-quantum geometry first, before hastening to make assumptions about what higher quantum geometry should be like. First things first. In any case, it is not a fault or omission of higher pre-quantum geometry not to feature derived geometry and non-degenerate shifted symplectic form, rather this is the nature of the subject of Lagrangian field theory. Or so I think.

    • CommentRowNumber8.
    • CommentAuthorDavid_Corfield
    • CommentTimeMar 2nd 2018

    And the extension to look at differential graded algebroids belongs to same approach? I see from this abstract that your former student is developing this:

    we explain how to apply this machinery to the case of non-split formal moduli problems under a given derived affine scheme; this situation has been dealt with recently by Joost Nuiten, and requires to replace differential graded Lie algebras with differential graded Lie algebroids.

    • CommentRowNumber9.
    • CommentAuthorUrs
    • CommentTimeMar 2nd 2018
    • (edited Mar 2nd 2018)

    Now by “the same approach” you are referring to the general topic of rectification, right? Yes, the concept of dg-Lie algebroids is (or should be) the rectification of the concept of general \infty-Lie algebroids. To be more precise I would have called Joost’s def 2.1 in arXiv:1712.03442 that of dg-Lie-Rinehart pairs, but of course the difference is negligible in a context of dg-geometry.