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Constraining Dark Matter and Dark Energy Models using Astrophysical Surveys.

机译：使用天体物理测量法约束暗物质和暗能量模型。

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摘要

This thesis addresses astrophysical probes to constrain dark matter (DM) and dark energy models. Primordial black holes (PBHs) remain one of the few DM candidates within the Standard Model of Particle Physics. This thesis presents a new probe of this PBH DM, using the microlensing of the source stars monitored by the already existing Kepler satellite. With its photometric precision and the large projected cross section of the nearby stars, it is found that previous constraints on PBH DM could theoretically be extended by two orders of magnitude. Correcting a well-known microlensing formula, a limb-darkening analysis is included, and a new approximation is calculated for future star selection. A preliminary prediction is calculated for the planned Wide-Field Infrared Survey Telescope.;A preliminary study of the first two years of publicly available Kepler data is presented. The investigation yields many new sources of background error not predicted in the theoretical calculations, such as stellar flares and comets in the field of view. Since no PBH candidates are detected, an efficiency of detection is therefore calculated by running a Monte Carlo with fake limb-darkened finite-source microlensing events. It is found that with just the first 8 quarters of data, a full order of magnitude of the PBH mass range can be already constrained.;Finally, one of the astrophysical probes of dark energy is also addressed - specifically, the baryon acoustic oscillations (BAO) measurement in the gas distribution, as detected in quasar absorption lines. This unique measurement of dark energy at intermediate redshifts is being measured by current telescope surveys. The last part of this thesis therefore focuses on understanding the systematic effects in such a detection. Since the bias between the underlying dark matter distribution and the measured gas flux distribution is based on gas physics, hydrodynamic simulations are used to understand the evolution of neutral hydrogen over time. It is found the location of the peak is a dependable measurement, but more robust simulations will have to be run for a full understanding of the shape and size of the peak.
机译：本文讨论了限制暗物质（DM）和暗能量模型的天体探测。原始黑洞（PBHs）仍然是粒子物理标准模型中为数不多的DM候选物之一。本文利用由已存在的开普勒卫星监视的源恒星的微透镜，提出了这种PBH DM的新探测器。凭借其光度测量精度和附近恒星的大投影截面，发现从理论上讲，PBH DM的先前限制可以扩展两个数量级。校正了众所周知的微透镜公式，包括了肢体变暗分析，并且为将来的恒星选择计算了一个新的近似值。为计划中的广域红外勘测望远镜计算了初步的预测。提出了对前两年公开可用的开普勒数据的初步研究。研究产生了许多新的背景误差来源，这些理论误差是理论计算中无法预测的，例如恒星耀斑和彗星。由于未检测到PBH候选物，因此通过运行带有假肢变深的有限光源微透镜事件的蒙特卡洛计算检测效率。发现仅使用前八分之四的数据，PBH质量范围的整个数量级就已经受到约束。最后，还解决了暗能量的天体探测之一-特别是重子声振荡（ BAO）测量气体分布，如在类星体吸收线中检测到的。当前的望远镜调查正在测量这种在中间红移时暗能量的独特测量。因此，本论文的最后一部分着重于了解这种检测中的系统效果。由于潜在的暗物质分布与测得的气体通量分布之间的偏差基于气体物理学，因此使用流体动力学模拟来了解中性氢随时间的演变。已发现峰的位置是可靠的测量，但是必须运行更可靠的仿真才能完全了解峰的形状和大小。

著录项

  • 作者

    Cieplak, Agnieszka M.;

  • 作者单位

    University of California, San Diego.;

  • 授予单位 University of California, San Diego.;
  • 学科 Physics Theory.;Physics Astrophysics.
  • 学位 Ph.D.
  • 年度 2013
  • 页码 118 p.
  • 总页数 118
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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