宇宙距离二重性关系的应用和中微子性质的限制

发布时间：2018-03-09 10:46

本文选题：观测宇宙学　切入点：宇宙距离尺度　出处：《南京大学》2013年硕士论文　论文类型：学位论文

【摘要】：观测宇宙学在近十几年内发展迅速。很多新鲜的观测方法技术和探针被不断地开发,很多重要的科学发现也因此给我们对宇宙的认识带来了革命性的影响。本文的工作主要基于对宇宙学探针数据的利用,从而进行连结理论与观测的现象学研究。第一章简单介绍了我们两方面工作的背景和研究动机。其一是关于使用宇宙距离二重性关系来检验星系团气体质量分数的测量,另一是使用宇宙学观测数据对中微子性质和暗能量状态方程的联合限制。在第二章中,我们提出了针对一些目前在星系团中测量得到的X射线气体质量分数(fgas)数据所进行的一致性检验。这种方法借助于Union2超新星的光度距离(DL)数据,并使用宇宙距离二重性关系,ηtheory=DL(1+z)-2/DA。我们并不像之前的一些分析一样给ηtheory设置一些红移参数化形式,而是固定ηtheory≡1,进而提取fgas数据与超新星观测同时偏好的宇宙学信息。在处理Union2超新星数据时,我们采用了取bin的方法,从而达到减小统计误差的目的。四个X射线气体质量分数样本,即Allen等(两个样本)、LaRoque等和Ettori等,经由两种对fgas的理论模拟,在我们的工作中被细致地分析。对Allen等样本的分析结果证实了我们这种方法的可行性。我们的分析给出LaRoque等的样本所倾向的宇宙学与其参考宇宙学在1-σ置信度水平内吻合。但是对于Ettori等的fgas数据集,不自洽性可达高于3-σ置信度水平。此数据集展现出对ΩA=0宇宙学的特殊偏好。第三章主要围绕我们对中微子性质的宇宙学限制展开。使用很多宇宙学观测数据,包括宇宙微波背景辐射各向异性观测(WMAP卫星第7年数据)、弱引力透镜观测(CFHTLS项目第3年数据)、重子声波震荡观测(SDSS和WiggleZ项目数据)、最新的Hubble膨胀率的观测、Union2.1Ia型超新星的观测数据以及HST卫星对Hubble常数的测量结果,我们对中微子的总质量参数(∑mv)、中微子的有效代数参数(Neff)和暗能量的状态方程参数(w)进行分别的以及联合的限制。我们发现如果Neff和w被固定不动,所有数据的确可以联合给出一个∑mv的很低的上限。但是,一旦Neff和w可以自由变化,原先紧致的上限会遭到严重的削弱。我们的这一发现,对之前所有文献里所谓的“精确的中微子质量总和的上限”的严谨性提出了重大疑问。在我们的研究中,针对最一般性的情况(即使用所有的数据,放开所有的参数),那三个关键参数的限制结果是∑mν=0.556+0.231-0.288eV、Neff=3.839±0.452和w=-1.058±0.088,在68%置信度区间。我们的结果给出了中微子总质量的1-σ下限、支持最近发现的偏离标准大爆炸核合成所预期的三味中微子的额外自由度、并且支持宇宙学常数暗能量模型。另外我们还发现如果暗能量状态方程参数固定,目前的弱引力透镜数据在限制其他宇宙学参数时体现出了一定的能力。同样,在w=-1的前提下,Hubble膨胀率的观测数据体现出了很多超越超新星数据的地方,尤其是其对Neff的精确限制。不过,只要w作为一个自由参数变化,始终是超新星这一标准烛光数据在参数限制中起主导作用。最后我们对本文所介绍的工作加以总结,并提出研究展望。
[Abstract]:The observational cosmology developed rapidly in recent years. A lot of new observation methods and probe technology being developed, many important scientific discoveries and therefore to our understanding of the universe has brought a revolutionary influence. The main work of this paper is based on the use of probe data to cosmology, linking theory and observation of phenomenological research.
The first chapter briefly introduces the background of our two aspects of the work and motivation of the study. One is about the use of measurements of the cosmic distance duality relation to test the cluster gas mass fraction, the other is the use of cosmological observations combined data constraints on neutrino properties and the equation of state of dark energy.
In the second chapter, we put forward some present in the cluster are measured by X - ray gas mass fraction (fgas) consistency test of data. By this method in the luminosity distance Union2 supernova (DL) data, and using the cosmic distance duality relation, theory=DL (1+z) analysis before we don't like -2/DA. to set some parametric form of ETA theory redshift, but fixed ETA theory = 1, and the observation of supernova cosmology information and extracting fgas data at the same time preference. In the processing of Union2 supernova data, we used the methods of bin, in order to minimize the statistical error. Four X - ray gas mass fraction of samples, namely Allen (two samples), LaRoque and Ettori, through two kinds of simulation of fgas theory, by careful analysis in our work. The analysis results of Allen samples We confirmed the feasibility of this method. We analyzed LaRoque cosmology of the sample and reference tendency of cosmology in the 1- sigma level of confidence in agreement. But for the fgas Ettori data set, not self consistent is higher than that of 3- sigma confidence level. This data set to show special preference for A=0. Cosmology.
The third chapter focuses on our cosmological constraints on neutrino properties. Many cosmological observations, including the cosmic microwave background radiation anisotropy (WMAP satellite observation data of seventh years), weak lensing observations (CFHTLS project third years of data), baryon acoustic shock observation (SDSS and WiggleZ project, the latest observation data) Hubble the rate of expansion, measurement results of Hubble constant Union2.1I a supernova observational data and HST satellite, we might total quality parameters (sigma MV), effective algebraic parameters of neutrinos (Neff) and parameters of the dark energy equation of state (W) respectively and combined with constraints. We found that if Neff and the W is fixed, all data can indeed be combined to give a sigma MV very low limit. However, when Neff and W are free to change the original compact limit will be severely weakened. It found that, prior to the so-called "total neutrino mass accurate limit" in the literature all rigor presents great doubt. In our study, according to the general situation (i.e. using all the data, the release of all parameters), the three key parameters of the limit results is m v =0.556+0.231-0.288eV, Neff=3.839 + 0.452 and w=-1.058 + 0.088, 68% confidence interval. Our results are given 1- sigma lower total neutrino mass, additional degrees of freedom in support of the recent discovery of deviation from the standard Big Bang nucleosynthesis expected three neutrino, and supports the cosmological constant dark energy model. In addition we also found that if the dark energy equation of state parameter fixed, weak lensing data present in other cosmological parameters show a certain ability. Similarly, in the w=-1 under the premise of the Hubble expansion rate of view The measurement data reflect many places beyond the supernova data, especially its precise restriction on Neff. However, as long as w changes as a free parameter, the standard candlelight data always play a leading role in the parameter restriction.
Finally, we summarize the work introduced in this paper and put forward the prospect of the research.

【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P159

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