arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2302.13490hep-th
收藏

再论BPS黑洞熵的定域性

Revisiting localization for BPS black hole entropy

Ashoke Sen

摘要:

宏观计算BPS黑洞的简并度/指数需要在黑洞的近视界几何上进行弦论路径积分。有人建议,路径积分可以本地化到一个有限维的子空间,利用不间断的超对称性的近地平线几何。我们讨论了在宣布胜利之前需要解决的几个问题:(1)由于Killing旋量在我们接近近视界几何的渐近边界时呈指数增长,因此动力学算子的δ函数可归一化本征模不形成超对称代数的表示,(2)来自各种单圈决定子的对数贡献对紫外截止敏感,因此没有紫外截止的详细知识-(3)指数定理的结果表明,至少在二次阶上,存在比目前所考虑的更多的局域化作用的平坦方向.我们还讨论了局部化技术在度规和引力子的零模上进行路径积分的有限应用,并得到了有限的答案。这与arXiv:0905.2686的结果一致,并且表明对于计算BPS黑洞熵,没有必要使用超施瓦茨作用来调节这些零模式上的路径积分。

英文摘要:

Macroscopic computation of the degeneracy / index of a BPS black hole requires carrying out string theory path integral over the near horizon geometry of the black hole. It has been suggested that the path integral can be localized to a finite dimensional subspace using the unbroken supersymmetries of the near horizon geometry. We discuss several issues that need to be resolved before one can declare victory: (1) delta-function normalizable eigenmodes of the kinetic operator do not form a representation of the supersymmetry algebra since the Killing spinors grow exponentially as we approach the asymptotic boundary of the near horizon geometry, (2) the logarithmic contributions coming from various one loop determinants are sensitive to the ultraviolet cut-off and therefore without detailed knowledge of the ultraviolet cut-off one cannot determine the order one correction to the entropy that could depend on the ratios of the charges, (3) the results of index theorem indicate that there are additional flat directions of the localization action, at least at the quadratic order, than what has been considered so far. We also discuss a limited application of localization techniques to carry out the path integral over the zero modes of the metric and the gravitino, and get a finite answer. This is consistent with the results of arXiv:0905.2686 and shows that for computing BPS black hole entropy it is not necessary to regulate the path integral over these zero modes using the super-Schwartzian action.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑