On Fractional Instanton Numbers in Six Dimensional Heterotic E8 x E8 Orbifolds

Abstract

We derive the precise relation between level matching condition and fractional instanton numbers in six dimensional, abelian and supersymmetric orbifolds of E8 x E8 heterotic string theory. The fractional part of the two E8 instanton numbers is explicitly calculated in terms of the gauge twist. This relation is then used to show that the classification of these orbifolds can be given in terms of flat bundles away from the orbifold singularities under the only constraint that the sum of the fractional parts of the gauge instanton numbers match the fractional part of the gravitational instanton number locally at every fixed point. This directly carries over to M-theory on S^1/Z_2

latex2e, 12 pages; reference and comments added

References in corpus (4)

• Intersecting Orbifold Planes and Local Anomaly Cancellation in M-Theory
• On the Duality between Perturbative Heterotic Orbifolds and M-Theory on T^4/Z_N
• Local Anomaly Cancellation, M-Theory Orbifolds and Phase-Transitions
• An M-Theory Perspective on Heterotic K3 Orbifold Compactifications

Cited by in corpus (7)

• Heterotic Moduli Stabilization with Fractional Chern-Simons Invariants
• Heterotic Brane World
• Resolutions of C^n/Z_n Orbifolds, their U(1) Bundles, and Applications to String Model Building
• Double-Scaling Limit of Heterotic Bundles and Dynamical Deformation in CFT
• The Abelian Heterotic Conifold
• Chern-Simons Invariants and Heterotic Superpotentials
• On Fractional Instanton Numbers in Six Dimensional Heterotic E_8 x E_8 Orbifolds