Residues and world sheet instantons
Residues and world sheet instantons
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留数和世界片瞬子
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
E. Witten
中科院分区：
文献类型：
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作者：
C. Beasley;E. Witten
我们重新考虑的问题，其中卡-丘紧化的杂化弦是稳定的世界表瞬子修正的有效时空超势。例如，由（0，2）线性西格玛模型描述的紧化被认为是稳定的，这表明这些理论中的瞬子效应之间存在显著的抵消作用。在这里，我们表明，这种取消直接遵循留数定理，其证明仅依赖于右移动世界片超对称性和适当的紧性性质的（0，2）线性西格玛模型。我们的留数定理也扩展到一类新的“半线性”sigma模型。利用这些半线性模型，我们证明了在CP 4中的五次超曲面上的杂合紧化是稳定的。最后，我们应用类似的思想来计算G2完整性流形上M理论紧化中膜瞬子族的超势贡献。
We reconsider the question of which Calabi-Yau compactifications of the heterotic string are stable under world-sheet instanton corrections to the effective space-time superpotential. For instance, compactifications described by (0,2) linear sigma models are believed to be stable, suggesting a remarkable cancellation among the instanton effects in these theories. Here, we show that this cancellation follows directly from a residue theorem, whose proof relies only upon the right-moving world-sheet supersymmetries and suitable compactness properties of the (0,2) linear sigma model. Our residue theorem also extends to a new class of ``half-linear'' sigma models. Using these half-linear models, we show that heterotic compactifications on the quintic hypersurface in CP4 for which the gauge bundle pulls back from a bundle on CP4 are stable. Finally, we apply similar ideas to compute the superpotential contributions from families of membrane instantons in M-theory compactifications on manifolds of G2 holonomy.