Searching for Stochastic Gravitational-Wave Background with LIGO: Data Analysis and Detector Development

该项目的重点是寻找随机引力波背景（SGWB）。特别是，搜索将通过对LIGO观测站在最近的LIGO科学运行（S5）期间获得的数据进行交叉相关来进行，并且在即将到来的科学运行（S6）期间将利用LIGO探测器更好的灵敏度。这些搜索将建立世界上最灵敏的引力波能量密度测量。此外，将进行一项研究，以评估先进LIGO的重力梯度噪声：重力梯度噪声预计将限制先进LIGO探测器在最低频率的灵敏度，这是最敏感的SGWB。SGWB预计将在宇宙历史的最早阶段产生。因此，对SGWB的直接观测将提供一个非常年轻的宇宙的一瞥，比使用其他天体物理技术可能的要年轻得多。它也将是对最高能量粒子物理学的一个非常罕见的探测，目前基于加速器的粒子物理学实验无法访问。SGWB也可能是由大量剧烈的天体物理事件产生的，如伽马射线爆发或超新星。因此，对SGWB的直接观测也将提供有关这些奇异事件的信息。该项目将允许本科生和研究生以及博士后学者直接参与宇宙学和天体物理学这一非常令人兴奋的领域，并为其做出重大贡献。该项目还包括建立一个可在网上访问的SGWB领域的模型和实验档案，从而为宇宙学和天体物理学界以及非科学受众提供更广泛的教育影响。

This project focuses on searches for the stochastic gravitational-wave background (SGWB). In particular, searches will be conducted by cross-correlating the data acquired by the LIGO observatories during the latest LIGO science run (S5), and during the upcoming science run (S6) which will take advantage of the better sensitivity of LIGO detectors. These searches will establish the world's most sensitive measurements of the energy density of gravitational waves. Moreover, a study will be performed to assess the gravity gradient noise for Advanced LIGO: the gravity gradient noise is expected to limit the sensitivity of Advanced LIGO detectors at lowest frequencies, which are most sensitive to the SGWB.The SGWB is expected to be produced in the earliest stages in the history of the Universe. Hence, direct observation of the SGWB would provide a glimpse of a very young Universe, much younger than what is possible using other astrophysical techniques. It would also represent a very rare probe of the particle physics of the highest energies, currently not accessible to accelerator-based particle physics experiments. The SGWB could also be produced by a large number of violent astrophysical events, such as gamma ray bursts or supernovae. Hence, direct observation of the SGWB would provide information about these exotic events as well. This project will allow undergraduate and graduate students, and postdoctoral scholars to be directly involved in this very exciting field of cosmology and astrophysics, and to make significant contributions to them. The project also includes building a web-accessible archive of models and experiments in the field of SGWB, hence providing a broader educational impact on the cosmology and astrophysics communities, as well as on non-scientific audience.