Large-scale structure as a probe of inflation and galaxy formation physics

大型结构作为暴胀和星系形成物理学的探针

• 批准号: 2159980
• 金额: --
• 依托单位: Liverpool John Moores University
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2159980
• 关键词: Large; scale; structure; probe; inflation

The distribution of matter on the largest scales and its evolution over time can be used to constrain cosmological models. Comparisons of existing large-scale structure measurements with those of the cosmic microwave background, which probes the Universe at early times, show mild evidence for tension. This tension can potentially be resolved by appealing to extensions of the standard model of cosmology and/or untreated systematic errors in the modelling of LSS, of which baryonic physics has been frequently suggested. We will revisit this tension using carefully calibrated cosmological hydrodynamical simulations, which thus capture the back reaction of the baryons on the total matter distribution. Furthermore, we will extend the BAryons and HAloes of MAssive Systems (BAHAMAS) simulations to assess the impact of uncertainties in the modelling of cosmic inflation. Inflation is an ad hoc addition to the hot big bang model that nicely accounts for many features of the observed Universe, however many of these successes are generic to inflation models of which there are many. Different models predict different amounts of deviation from a powerlaw in the initial power spectrum of density fluctuations. Through direct simulation and comparison to observations, we will provide rigorous constraints on the degree of so-called "running" of the primordial power spectrum spectral index and will assess whether non-standard inflation models can resolve the aforementioned tension.

物质在最大尺度上的分布及其随时间的演化可以用来约束宇宙学模型。将现有的大尺度结构测量结果与宇宙微波背景辐射的测量结果进行比较，在早期探测宇宙，显示出张力的温和证据。这种紧张局势可以通过呼吁宇宙学标准模型的扩展和/或LSS模型中未经处理的系统误差来解决，其中重子物理学经常被建议。我们将使用仔细校准的宇宙流体动力学模拟来重新审视这种张力，从而捕获重子对总物质分布的反作用。此外，我们将扩展大规模系统（BAHAMAS）模拟的BAryons和HAloes，以评估宇宙膨胀模型中不确定性的影响。暴胀是对热大爆炸模型的一个特别补充，它很好地解释了观测到的宇宙的许多特征，然而这些成功中的许多都是暴胀模型的通用模型，其中有很多。不同的模型预测不同数量的偏离幂律在初始功率谱的密度波动。通过直接模拟和比较观测，我们将提供严格的约束的程度，所谓的“运行”的原始功率谱谱指数，并将评估是否非标准的通货膨胀模型可以解决上述紧张局势。

项目成果

Exploring extensions to the standard cosmological model and the impact of baryons on small scales

• DOI: 10.1093/mnras/staa2059
• 发表时间: 2020-04
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: Sam G Stafford;Shaun T. Brown;I. McCarthy;A. Font;A. Robertson;Robert Poole-Mckenzie

The bahamas project: effects of a running scalar spectral index on large-scale structure

• DOI: 10.1093/mnras/staa129
• 发表时间: 2019-07
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: Sam G Stafford;I. McCarthy;R. Crain;J. Salcido;J. Schaye;A. Font;J. Kwan;S. Pfeifer