arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节（Veterans Day），12 日无更新
arXiv 1806.02206hep-thgr-qc
收藏

量子引力、可重整化性与量子态不变性

Quantum gravity, renormalizability and diffeomorphism invariance

Tim R. Morris

备注：
64 pages
发表信息：
SciPost Phys. 5, 040 (2018)
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

我们表明，威尔逊重整化群（RG）提供了一个自然的正则化的量子主方程，使一阶的BRST代数关闭本地泛函跨越本征算子与常数耦合。然后我们将其应用于量子引力。在高斯不动点附近，度规的共形因子的RG性质允许构造可重整化相互作用的希尔伯特空间$\mathfrak{L}$，在$\hbar$中是非微扰的，并且涉及任意高幂的引力涨落。我们发现，违反了反同态不变性的相互作用，躺在里面$\mathfrak{L}$，在这个意义上说，只有一个平凡的量子BRST上同调存在的相互作用在一阶的耦合。然而，通过对$\mathfrak{L}$的边界进行限制，耦合可以被约束以恢复牛顿常数，并且标准实现了自同构不变性，同时保留了可重整性。该限制是足够灵活的，以允许这也在更高的订单。这留下了一些问题，应该在第二顺序找到答案。我们开发了大部分允许执行这些计算的框架。

英文摘要：

We show that the Wilsonian renormalization group (RG) provides a natural regularisation of the Quantum Master Equation such that to first order the BRST algebra closes on local functionals spanned by the eigenoperators with constant couplings. We then apply this to quantum gravity. Around the Gaussian fixed point, RG properties of the conformal factor of the metric allow the construction of a Hilbert space $\mathfrak{L}$ of renormalizable interactions, non-perturbative in $\hbar$, and involving arbitrarily high powers of the gravitational fluctuations. We show that diffeomorphism invariance is violated for interactions that lie inside $\mathfrak{L}$, in the sense that only a trivial quantum BRST cohomology exists for interactions at first order in the couplings. However by taking a limit to the boundary of $\mathfrak{L}$, the couplings can be constrained to recover Newton's constant, and standard realisations of diffeomorphism invariance, whilst retaining renormalizability. The limits are sufficiently flexible to allow this also at higher orders. This leaves open a number of questions that should find their answer at second order. We develop much of the framework that will allow these calculations to be performed.

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。

↑