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arXiv 2011.05305hep-th
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量子电动力学中的规范不变传播子与态

Gauge Invariant Propagators and States in Quantum Electrodynamics

Jordan Wilson-Gerow, P. C. E. Stamp

AI总结:

本文在标量和旋量QED中,通过规范不变路径积分边界数据研究规范不变态,并利用规范不变传播子自然导出时间切片与零无穷远上的库仑场及软光子dressing因子。

摘要:

我们研究量子电动力学(QED)中的规范不变态,其中态被理解为生活在规范不变路径积分边界上的数据。这一处理同时适用于标量QED和旋量QED,边界既可以是时间切片,也可以是“因果菱形”的边界。我们讨论两种情形:一种是规范场在边界处衰减为零,另一种是“大规范变换”情形,此时规范场在边界处保持有限。动力学通过规范不变传播子进行讨论,该传播子描述粒子与场在边界之间的运动。我们展示了路径积分如何自然地生成一个“库仑场” dressing 因子,用于生活在时间切片上的态,并且这一过程无需固定任何规范。我们证明 dressing 的形式只取决于边界的性质。我们还推导了定义在零无穷远上的态的类似 dressing,同时展示其库仑部分以及软光子部分。

英文摘要:

We study gauge invariant states in QED, where states are understood in terms of data living on the boundary of gauge invariant path-integrals. This is done for both scalar and spinor QED, and for boundaries that are either time slices, or the boundaries of a 'causal diamond'. We discuss both the case where the gauge field falls off to zero at the boundaries, and the case of 'large gauge transformations', where it remains finite at the boundaries. The dynamics are discussed using the gauge-invariant propagator, describing motion of both the particles and the field between the boundaries. We demonstrate how the path-integral naturally generates a 'Coulomb-field' dressing factor for states living on time-slices, and how this is done without fixing any gauge. We show that the form of the dressing depends only on the nature of the boundaries. We also derive the analogous dressing for states defined on null infinity, showing both its Coulombic parts as well as soft-photon parts.

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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