Absolutely: If a direct -factor in the equivariance group is singled out as on the bottom of p. 32 here — and if that acts by “Real involution” on whatever cohomology coeffcients one has— then its fixed loci are the orientifolds.
]]>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.
]]>added publication data to:
added pointer to:
I wrote a section (here) on orientifold backreaction (or not), with some discussion of and quotes from the literature.
]]>added pointer to today’s
(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)
]]>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
]]>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 -brane involutions in Prop. 4.7 of our “Real ADE-equivariant (co-)homotopy”
]]>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.
]]>have added more details on the Jandl-gerbe model and its relation to the DFM-model.
]]>added to orientifold some basic notions on orientifold circle -bundles.
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