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arXiv 1709.10076astro-ph.COhep-th
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随机势中的多场暴胀

Manyfield Inflation in Random Potentials

Theodor Bjorkmo, M. C. David Marsh

摘要:

我们构建了具有许多随机相互作用场的暴胀模型,并利用这些模型来研究宇宙学观测量的产生。我们建模的潜力作为多维高斯随机场(GRF),并确定强大的代数简化,第一次,使人们有可能访问的多场极限的通货膨胀GRF潜力。专注于小场,慢卷,近似鞍点膨胀的潜力与亚普朗克尺度上的结构,我们构建了明确的例子,涉及多达100个领域,并生成统计合奏包括164,000模型,涉及5至50个领域。对于支持至少60个e-折叠暴胀的子集,我们使用“传输方法”和$δN$形式主义来确定暴胀结束时宇宙学观测值的预测,包括原始扰动的功率谱和局部非高斯性。我们发现三个关键结果:i)普朗克相容性并不罕见,但未来的实验可能会排除这类模型; ii)在多场极限下,这些模型的预测与以前的结果吻合得很好,但比以前的结果更尖锐,这些结果是使用通过非平衡随机矩阵理论构建的势得出的; iii)尽管有大量的多场效应,非高斯性通常非常小:$f_{\rm nl}^{\rm loc} \ll 1$。我们的结论是,许多“通用预测”的单场膨胀可以紧急功能的复杂的通货膨胀模型。

英文摘要:

We construct models of inflation with many randomly interacting fields and use these to study the generation of cosmological observables. We model the potentials as multi-dimensional Gaussian random fields (GRFs) and identify powerful algebraic simplifications that, for the first time, make it possible to access the manyfield limit of inflation in GRF potentials. Focussing on small-field, slow-roll, approximate saddle-point inflation in potentials with structure on sub-Planckian scales, we construct explicit examples involving up to 100 fields and generate statistical ensembles comprising of 164,000 models involving 5 to 50 fields. For the subset of these that support at least sixty e-folds of inflation, we use the 'transport method' and $δN$ formalism to determine the predictions for cosmological observables at the end of inflation, including the power spectrum and the local non-Gaussianities of the primordial perturbations. We find three key results: i) Planck compatibility is not rare, but future experiments may rule out this class of models; ii) In the manyfield limit, the predictions from these models agree well with, but are sharper than, previous results derived using potentials constructed through non-equilibrium Random Matrix Theory; iii) Despite substantial multifield effects, non-Gaussianities are typically very small: $f_{\rm nl}^{\rm loc} \ll 1$. We conclude that many of the 'generic predictions' of single-field inflation can be emergent features of complex inflation models.

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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