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

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 complex-geometry computable-mathematics computer-science constructive cosmology definitions deformation-theory descent diagrams differential differential-cohomology differential-equations differential-geometry digraphs duality elliptic-cohomology enriched fibration foundation foundations functional-analysis functor gauge-theory gebra geometric-quantization geometry 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 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 monad monads monoidal monoidal-category-theory morphism motives motivic-cohomology nforum nlab noncommutative noncommutative-geometry number-theory 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 stack string string-theory superalgebra supergeometry svg symplectic-geometry synthetic-differential-geometry terminology theory topology topos topos-theory tqft 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.
    • CommentAuthorUrs
    • CommentTimeApr 25th 2011

    added to orientifold some basic notions on orientifold circle nn-bundles.

    • CommentRowNumber2.
    • CommentAuthorUrs
    • CommentTimeApr 25th 2011

    have added more details on the Jandl-gerbe model and its relation to the DFM-model.

    • CommentRowNumber3.
    • CommentAuthorUrs
    • CommentTimeApr 4th 2014

    I have rewritten the first paragraphs of orientifold and removed some of the technical discussion that I had there. Will write an improved version these days.

    • CommentRowNumber4.
    • CommentAuthorUrs
    • CommentTimeOct 2nd 2018

    Have expanded the list of references. In particular I added pointer to Hanany-Kol 00, which, as I just discovered, gives on its p 11 a lightning sketch of the classification of those pp-brane involutions in Prop. 4.7 of our “Real ADE-equivariant (co-)homotopy

    diff, v42, current

    • CommentRowNumber5.
    • CommentAuthorUrs
    • CommentTimeMay 12th 2019
    • (edited May 12th 2019)

    added pointer to this reference:

    (didn’t realize before that Ron Maimon has such a publication – or maybe I am misidentifying the author?)

    Also slightly re-arranged the references, putting all the M-theory lifts into their own subsection

    diff, v55, current

    • CommentRowNumber6.
    • CommentAuthorUrs
    • CommentTimeMay 12th 2019

    (whether it’s him or not, it’s fun getting distracted from googling his online writings; here he explains that the orgies at Harvard are “not done well”, in contrast to those at Cornell, and why)

    • CommentRowNumber7.
    • CommentAuthorUrs
    • CommentTimeMay 16th 2019

    added pointer to today’s

    diff, v62, current

    • CommentRowNumber8.
    • CommentAuthorUrs
    • CommentTimeMar 18th 2020

    I wrote a section (here) on orientifold backreaction (or not), with some discussion of and quotes from the literature.

    diff, v80, current

    • CommentRowNumber9.
    • CommentAuthorUrs
    • CommentTimeSep 8th 2020

    added pointer to:

    diff, v86, current

    • CommentRowNumber10.
    • CommentAuthorUrs
    • CommentTimeSep 18th 2020

    added publication data to:

    diff, v87, current

    • CommentRowNumber11.
    • CommentAuthorperezl.alonso
    • CommentTimeOct 20th 2023

    But isn’t there a concrete definition as for orbifold in orbifold groupoid? Of the resources I’ve checked out (which are admittedly not many) they just “define” them in terms of what they’re supposed to do.

    • CommentRowNumber12.
    • CommentAuthorUrs
    • CommentTimeOct 20th 2023

    Absolutely: If a direct /2\mathbb{Z}/2-factor in the equivariance group is singled out as on the bottom of p. 32 here — and if that /2\mathbb{Z}/2 acts by “Real involution” on whatever cohomology coeffcients one has— then its fixed loci are the orientifolds.