Completely regular quantum stress tensor with w<-1
Completely regular quantum stress tensor with w<-1
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DOI：
10.1103/physrevd.81.023508
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发表时间：
2009-04
影响因子：
5
通讯作者：
E. Kahya;V. Onemli;R. Woodard
中科院分区：
文献类型：
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作者：
E. Kahya;V. Onemli;R. Woodard
对于宇宙学中的许多量子场论计算，不可能使用平坦空间的技巧，通过在无限时间内演化自由状态来获得完整的相互作用状态。状态波泛函必须在有限时间内指定，尽管自由状态足以获得最低阶效应，但高阶修正必然涉及初始状态的变化。如果不能正确地改变初始状态，可能会导致有效的场方程在初始值表面上发散，或者包含繁琐的红移项和，如比例因子的反幂。本文验证了2004年提出的一个猜想，即在非动态de Sitter背景下，具有四次自相互作用的无质量最小耦合标量的应力张量的初始值散度和双环期望值（在自由，Bunch-Davies真空中）的所有红移项的最低阶初始状态修正确实可以吸收。
For many quantum field theory computations in cosmology it is not possible to use the flat space trick of obtaining full, interacting states by evolving free states over infinite times. State wave functionals must be specified at finite times and, although the free states suffice to obtain the lowest order effects, higher order corrections necessarily involve changes of the initial state. Failing to correctly change the initial state can result in effective field equations which diverge on the initial value surface, or which contain tedious sums of terms that redshift like inverse powers of the scale factor. In this paper we verify a conjecture from 2004 that the lowest order initial state correction can indeed absorb the initial value divergences and all the redshifting terms of the two-loop expectation value (in free, Bunch-Davies vacuum) of the stress tensor of a massless, minimally coupled scalar with a quartic self-interaction on a nondynamical de Sitter background.