标题： BPS 五膜星 II：涨落 显示英文标题

标题： BPS Fivebrane Stars II: Fluctuations

摘要： 我们研究了1/2-BPS束缚态中$n_1$个基本弦和$n_5$个NS5膜的度规分量的量子涨落。 在$1/(n_1n_5)$的展开中，首阶贡献通过分析和数值方法的结合进行计算。 我们发现，在远离源的小距离处，涨落很小，与6维普朗克尺度相当。 将这一结果与文献中对最大混合态涨落的分析进行比较，我们得出结论，之前对于后者的大型涨落是统计性的而非量子性的，并且微扰弦理论能够准确描述这些背景。 显示英文摘要

摘要： We investigate quantum fluctuations of metric components in coherent 1/2-BPS bound states of $n_1$ fundamental strings and $n_5$ NS5-branes. The leading order contribution in an expansion in $1/(n_1n_5)$ is calculated via a combination of analytical and numerical methods. We find that the fluctuations are small away from a tiny distance from the source, comparable to the 6d Planck scale. Comparing this result with an analysis in the literature of fluctuations in the maximally mixed state, we conclude that the large fluctuations previously found for the latter are statistical rather than quantum in nature, and that perturbative string theory provides an accurate description of these backgrounds.