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Baryonic Acoustic Oscillations in Large-Scale Structures

大型结构中的重子声振荡

基本信息

批准号：
2113850
负责人：
金额：
--
依托单位：
University of Cambridge
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-2113850
关键词：
Baryonic Acoustic Oscillations Large Scale

项目摘要

The upcoming Dark Energy Spectroscopic Instrument (DESI) will measure the positions of numerous galaxies and measure the effect of dark energy on the expansion of the universe. By estimating the power spectrum monopole from the galaxy clustering in the Universe I can deduce information about the geometry of space-time. From the latter I will measure the baryon acoustic oscillations in the power spectrum of the galaxy clustering data of the DESI collaboration. This will allow me, by applying advanced statistical methods such as Monte Carlo Markov Chain models, to deduce constraints for cosmological parameters. Separating the measurement of the power spectrum in a component along the line of sight and perpendicular to it, I will be able to measure the Alcock-Paczynski test with both the redshift space distortion and baryon acoustic oscillations signals. The Alcock-Paczynski test describes a distortion in an otherwise isotropic feature in the galaxy clustering when the assumed fiducial cosmological model used to transfer the measured redshifts into distances deviates from the true cosmology. This anisotropic signal may appear degenerate with the redshift space distortion signal in a featureless power spectrum. Using the baryon acoustic oscillations signal, it will be possible to break this degeneracy and exploit all three signals, redshift space distortion, baryon acoustic oscillations and the Alcock-Paczynski effect for cosmological parameter constraints. Currently, I am working on an accurate and robust power spectrum estimator for simulated and real data. In the near future, we will subsequently add additional features to the model in order to extract the BAO signal.

即将到来的暗能量光谱仪（DESI）将测量许多星系的位置，并测量暗能量对宇宙膨胀的影响。通过估计宇宙中星系团的功率谱，我可以推断出时空几何的信息。从后者，我将测量重子声学振荡的功率谱的星系团的数据的DESI合作。这将允许我通过应用诸如蒙特卡罗马尔可夫链模型等先进的统计方法来推导宇宙学参数的约束。分离测量功率谱的分量沿着视线和垂直于它，我将能够测量的Alcock-Paczynski测试与红移空间失真和重子声振荡信号。Alcock-Paczynski检验描述了当用来将测量到的红移转换成距离的假设的基准宇宙学模型偏离真实宇宙学时，星系团中原本各向同性的特征会发生扭曲。这种各向异性信号在无特征的功率谱中可能与红移空间失真信号一起出现退化。使用重子声振荡信号，将有可能打破这种简并，并利用所有三个信号，红移空间失真，重子声振荡和Alcock-Paczynski效应的宇宙学参数约束。目前，我正在研究一个准确和强大的功率谱估计模拟和真实的数据。在不久的将来，我们将随后向模型中添加其他特征，以提取BAO信号。