论文标题
纯虚拟场理论的纯虚拟延伸量表不变场：量子重力
Purely virtual extension of quantum field theory for gauge invariant fields: quantum gravity
论文作者
论文摘要
量子重力扩展到包括纯虚拟的“云扇区”，使我们能够定义一组依赖点的可观察物，包括量规不变的度量和规格不变的物质字段，并在触及触及方面计算其脱壳相关功能。普通的壳上相关功能和$ s $矩阵元素不受影响。每个额外的扇区都是由云场制成的，它的抗议合作伙伴，“云固定”功能和一个云Faddeev-Popov的决定因素。其他字段纯粹是虚拟的，以确保没有幽灵传播。扩展是统一的。特别是，光学定理的脱壳，图形版本。计算着衣服标量，向量和重力的单循环两点函数。它们的吸收性部位是正，云独立的和独立的，而如果使用了非纯虚拟云，则它们是非物理的。我们说明了我们在量子重力中找到一组完整可观察物的方法与文献中可用的其他方法之间的差异。
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.
