2019/03/22 by Chris D. A. Blair, Blair, Chris D. A.
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Theory (hep-th) #hep-th
paper · pdf · doi:10.48550/arxiv.1903.09411
18 pages, contribution to the proceedings of the workshop "Dualities and Generalized Geometries", Corfu Summer Institute 2018
arxiv created 2019/03/22 · arxiv updated 2019/03/25
We consider quotients of string and M-theory by discrete subgroups of the U-duality group. This results in what we call O-folds, which are generalisations of orbifolds and orientifolds, and generically involve non-geometric identifications between physical coordinates and dual winding coordinates. A simple ℤ2 quotient encodes the half-maximal duality web, describing on the same footing the Hořava-Witten description of M-theory on an interval, the heterotic theories, and type II in the presence of orientifold planes. This can be analysed using exceptional field theory, including the introduction of extra vector multiplets at the fixed points. This is an overview of the paper [1], based on a talk given at the Corfu Summer Institute 2018.