Strong restriction on inflationary vacua from the local $gauge$ invariance III: Infrared regularity of graviton loops
Strong restriction on inflationary vacua from the local $gauge$ invariance III: Infrared regularity of graviton loops
复制标题
局部 $gauge$ 不变性对暴胀真空的强烈限制 III：引力子环的红外规律性
DOI：
10.1093/ptep/ptu071
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
T. Tanaka and Y. Urakawa
中科院分区：
文献类型：
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作者：
福田努;渋谷寛;小川了;松尾友和;森元祐介;松本拓也;大島仁;稲生恒明;水沢萌;青木茂樹;高橋覚;山田恭平;中村光廣;佐藤修;中野敏行;小松雅宏;長縄直崇;六條宏紀;北川暢子;三角尚治;他 J-PARC T60 Collaboration;T. Tanaka and Y. Urakawa
有人声称，在膨胀过程中产生的引力子的超哈勃模会使回路修正发散。即使我们引入红外线(IR)截止值作为一种临时但实用的正则化方法，我们也会遇到长期增长，这可能会导致足够持久的通货膨胀的微扰膨胀破裂。在这篇文章中，我们证明了关于引力子的IR病理可以归因于局域可见宇宙中存在剩余的几个自由度，就像绝热曲率扰动的情况一样。我们将证明，选择欧几里得真空作为初始态，可以保证在上述剩余算术变换下的不变性。我们还将证明，只要我们考虑局部宇宙中的agauge不变量，我们既不会遇到IR发散，也不会遇到长期增长。本文中的论点适用于一般单场模型的暴涨，直到足够高的微扰阶数。
It has been claimed that the super-Hubble modes of the graviton generated during inflation can make loop corrections diverge. Even if we introduce an infrared (IR) cutoff at a comoving scale as an ad hoc but practical method of regularization, we encounter secular growth, which may lead to the breakdown of perturbative expansion for a sufficiently long-lasting inflation. In this paper, we show that the IR pathology concerning the graviton can be attributed to the presence of residualgaugedegrees of freedom in the local observable universe, as in the case of the adiabatic curvature perturbation. We will show that choosing the Euclidean vacuum as the initial state ensures invariance under the above-mentioned residualgaugetransformations. We will also show that, as long as we consider agaugeinvariant quantity in the local universe, we encounter neither IR divergence nor secular growth. The argument in this paper applies to general single-field models of inflation up to a sufficiently high order in perturbation.