标题： 关于IIB超弦的精确四次有效作用 显示英文标题

标题： On the exact quartic effective action for the type IIB superstring

摘要： 我们提出了一个四点有效作用量，用于描述十维IIB型超弦的引力子、反对称二形式、标量场和轴子。 该作用量明确具有SL(2,Z)不变性，并且能够重现已知的树级结果。 在微扰论中，它对于NS-NS sector仅有单圈修正，推广了R^4项的非重整化定理。 最后，非微扰修正具有预期的形式，即它们可以被解释为来自具有多重电荷的单一D-瞬子效应。 显示英文摘要

摘要： We propose a four-point effective action for the graviton, antisymmetric two-forms, dilaton and axion of type IIB superstring in ten dimensions. It is explicitly SL(2,Z)-invariant and reproduces the known tree-level results. Perturbatively, it has only one-loop corrections for the NS-NS sector, generalizing the non-renormalization theorem of the R^4 term. Finally, the non-perturbative corrections are of the expected form, namely, they can be interpreted as arising from single D-instantons of multiple charge.