On heterotic orbifolds, M theory and type I' brane engineering

Elie Gorbatov*, Vadim S. Kaplunovsky, Jacob Sonnenschein, Stefan Theisen, Shimon Yankielowicz

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Hořavar-Witten M theory ↔ heterotic string duality poses special problems for the twisted sectors of heterotic orbifolds. In our previous paper we explained how in M theory the twisted states couple to gauge fields apparently living on M9 branes at both ends of the eleventh dimension at the same time. The resolution involves 7D gauge fields which live on fixed planes of the (T4/ℤN) × (diuble struck S sign 1/ℤ2) × ℝ5,1 orbifold and lock onto the 10D gauge fields along the intersection planes. The physics of such intersection planes does not follow directly from the M theory but there are stringent kinematic constraints due to duality and local consistency, which allowed us to deduce the local fields and the boundary conditions at each intersection. In this paper we explain various phenomena at the intersection planes in terms of duality between Hořava-Witten and type I′ superstring theories. The orbifold fixed planes are dual to stacks of D6 branes, the M9 planes are dual to O8 orientifold planes accompanied by D8 branes, and the intersections are dual to brane junctions. We engineer several junction types which lead to distinct patterns of 7D/10D gauge field locking, 7D symmetry breaking and/or local 6D fields. Another aspect of brane engineering is putting the junctions together; sometimes, the combined effect is rather spectacular from the HW point of view and the quantum numbers of some twisted states have to 'bounce' off both ends of the eleventh dimension before their heterotic identity becomes clear. Some models involve D6/O8 junctions where the string coupling diverges towards the orientifold plane. We use the heterotic ↔ HW ↔ I′ duality to predict what should happen at such junctions. For example, pinning down an NS5 half-brane to a definite location on a λ = ∞ O8 plane requires precisely four D6 branes.

Original languageEnglish
Pages (from-to)339-417
Number of pages79
JournalJournal of High Energy Physics
Issue number5
StatePublished - 1 May 2002


  • M-Theory
  • Superstrings and Heterotic Strings


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