A geometry for nongeometric string backgrounds
Abstract
A geometric string solution has background fields in overlapping coordinate patches related by diffeomorphisms and gauge transformations, while for a nongeometric background this is generalised to allow transition functions involving duality transformations. Nongeometric string backgrounds arise from Tduals and mirrors of flux compactifications, from reductions with duality twists and from asymmetric orbifolds. Strings in `Tfold' backgrounds with a local ntorus fibration and Tduality transition functions in O(n,n;Bbb Z) are formulated in an enlarged space with a T^{2n} fibration which is geometric, with spacetime emerging locally from a choice of a T^{n} submanifold of each T^{2n} fibre, so that it is a subspace or brane embedded in the enlarged space. Tduality acts by changing to a different T^{n} subspace of T^{2n}. For a geometric background, the local choices of T^{n} fit together to give a spacetime which is a T^{n} bundle, while for nongeometric string backgrounds they do not fit together to form a manifold. In such cases spacetime geometry only makes sense locally, and the global structure involves the doubled geometry. For open strings, generalised Dbranes wrap a T^{n} subspace of each T^{2n} fibre and the physical Dbrane is the part of the physical space lying in the generalised Dbrane subspace.
 Publication:

Journal of High Energy Physics
 Pub Date:
 October 2005
 DOI:
 10.1088/11266708/2005/10/065
 arXiv:
 arXiv:hepth/0406102
 Bibcode:
 2005JHEP...10..065H
 Keywords:

 High Energy Physics  Theory;
 Differential Geometry
 EPrint:
 28 Pages. Minor changes