Numerical evaluation of the bispectrum in multiple field inflation—the transport approach with code
Numerical evaluation of the bispectrum in multiple field inflation—the transport approach with code
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多场膨胀中双谱的数值评估——带代码的传输方法
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
D. Seery
中科院分区：
文献类型：
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作者：
M. Dias;J. Frazer;D. Mulryne;D. Seery
我们给出了具有任意数量的轻场或重场的正则膨胀的功率谱和双谱的完整的数值计算框架。我们的方法包括了环路展开中树级的所有相关影响，包括(i)视界出口附近生长模式和衰减模式之间的干扰；（ii）近视界出口和超视界尺度上物种间的相关性和耦合性；（iii）群众的贡献；（iv）耦合对重力的所有贡献。我们跟踪每个相关函数从真空状态到视界出口和超视界状态的演化，而不需要匹配计算的量子和经典部分；当集成时，我们的方法完全符合量子场论的树级Schwinger或“in-in”公式。本文给出了所有两点和三点相关函数演化所需的方程，并给出了适当的初始条件。最后的形式适合于计算|fNL|阶一或更小的模型中双谱的振幅、形状和尺度依赖性，这是未来欧几里得、DESI和LSST等星系调查的目标。作为一个例子，我们将我们的框架应用到一些例子中，第一次对它们的双光谱进行了定量准确的预测。两个附带的报告描述了实现该方法的公开可用软件包。
We present a complete framework for numerical calculation of the power spectrum and bispectrum in canonical inflation with an arbitrary number of light or heavy fields. Our method includes all relevant effects at tree-level in the loop expansion, including (i) interference between growing and decaying modes near horizon exit; (ii) correlation and coupling between species near horizon exit and on superhorizon scales; (iii) contributions from mass terms; and (iv) all contributions from coupling to gravity. We track the evolution of each correlation function from the vacuum state through horizon exit and the superhorizon regime, with no need to match quantum and classical parts of the calculation; when integrated, our approach corresponds exactly with the tree-level Schwinger or `in-in' formulation of quantum field theory. In this paper we give the equations necessary to evolve all two- and three-point correlation functions together with suitable initial conditions. The final formalism is suitable to compute the amplitude, shape, and scale dependence of the bispectrum in models with |fNL| of order unity or less, which are a target for future galaxy surveys such as Euclid, DESI and LSST. As an illustration we apply our framework to a number of examples, obtaining quantitatively accurate predictions for their bispectra for the first time. Two accompanying reports describe publicly-available software packages that implement the method.
通货膨胀多领域模型的预测
影响因子：
6.4
作者：
Frazer J
通讯作者：
Frazer J
影响因子：
6.3
作者：
Degrande, Celine;Duhr, Claude;Reiter, Thomas
通讯作者：
Reiter, Thomas