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arXiv 2207.12401hep-thgr-qchep-ph
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规范不变场的量子场论纯虚扩展:量子引力

Purely virtual extension of quantum field theory for gauge invariant fields: quantum gravity

Damiano Anselmi

AI总结:

本文通过引入纯虚“云扇区”扩展量子引力,定义了规范不变的度规与物质场等完整点依赖可观测量并微扰计算其离壳关联函数,证明了该扩展的幺正性及吸收部分的规范无关性。

摘要:

量子引力被扩展以包含纯虚“云扇区”,这使我们能够定义一套完整的点依赖可观测量,包括规范不变的度规和规范不变的物质场,并微扰地计算它们的离壳关联函数。普通的在壳关联函数和$S$矩阵元不受影响。每个额外扇区由一个云场、其反交换伙伴、一个“云固定”函数和一个云 Faddeev-Popov 行列式组成。附加场是纯虚的,以确保没有鬼粒子传播。该扩展是幺正的。特别是,离壳的、图示版本的光学定理成立。计算了修饰标量、矢量和引力子的单圈两点函数。它们的吸收部分是正的、与云无关且与规范无关,而如果使用非纯虚云,它们则是非物理的。我们阐明了我们处理量子引力中寻找完整可观测量集合问题的方法与文献中其他可用方法之间的差异。

英文摘要:

Quantum gravity is extended to include purely virtual "cloud sectors", which allow us to define a complete set of point-dependent observables, including a gauge invariant metric and gauge invariant matter fields, and calculate their off-shell correlation functions perturbatively. The ordinary on-shell correlation functions and the $S$ matrix elements are unaffected. Each extra sector is made of a cloud field, its anticommuting partner, a "cloud-fixing" function and a cloud Faddeev-Popov determinant. The additional fields are purely virtual, to ensure that no ghosts propagate. The extension is unitary. In particular, the off-shell, diagrammatic version of the optical theorem holds. The one-loop two-point functions of dressed scalars, vectors and gravitons are calculated. Their absorptive parts are positive, cloud independent and gauge independent, while they are unphysical if non purely virtual clouds are used. We illustrate the differences between our approach to the problem of finding a complete set of observables in quantum gravity and other approaches available in the literature.

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。

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