本文關(guān)鍵詞： 宇宙模型 觀測限制 狀態(tài)方程 距離對偶關(guān)系 不透明度　出處：《湖南師范大學(xué)》2012年博士論文　論文類型：學(xué)位論文

【摘要】：在過去的10-20年間,宇宙學(xué)從一門對觀測數(shù)據(jù)非�？释膶W(xué)科逐漸成為了一門依靠觀測數(shù)據(jù)來推動其發(fā)展的學(xué)科。對許多關(guān)鍵的參數(shù)(例如,物質(zhì)密度分?jǐn)?shù)Ωm,0,宇宙膨脹的減速因子q0)的測量精度可以控制在10%以內(nèi)。在1998年之前,人們一直認(rèn)為宇宙膨脹的速度是減小的,令人感到非常驚奇的是,Ia型超新星的觀測結(jié)果卻表明現(xiàn)今的宇宙正經(jīng)歷著一個加速膨脹的過程。基于這樣的觀測事實,人們推斷宇宙中存在一種能產(chǎn)生負(fù)壓強的物質(zhì)能量組分,即暗能量,并得出其占到宇宙總物質(zhì)能量的2/3左右。理解和認(rèn)識暗能量的性質(zhì)是現(xiàn)代物理學(xué)所面臨的最大挑戰(zhàn)之一。為了避開理解暗能量的奇異特性所帶來的挑戰(zhàn),人們認(rèn)為現(xiàn)有的愛因斯坦引力理論在宇宙的尺度上可能不再成立,而是需要對其進行適當(dāng)?shù)男拚?這些理論可以在不引入暗能量的情況下解釋宇宙的加速膨脹。 迄今為止,大量的宇宙學(xué)模型被建立。同時,不同的天文觀測所得到的數(shù)據(jù)樣本越來越大,精度越來越高。這些數(shù)據(jù)將為我們揭開暗能量的神秘面紗,或者理解大尺度時的引力規(guī)律提供有力依據(jù)。因此,將理論模型和實驗觀測結(jié)果聯(lián)系起來是非常必要的。本文前一部分討論了最新的觀測數(shù)據(jù)對一些主流的宇宙學(xué)模型的限制。我們發(fā)現(xiàn),真空暗能量模型(ACDM)還是最被觀測(SNLS3la型超新星,宙微波背景輻射和重子聲學(xué)振蕩的數(shù)據(jù),以及哈勃參數(shù)的數(shù)據(jù))所支持的候選者。然而,當(dāng)只考慮SNLS3la型超新星數(shù)據(jù)時,DGP(膜世界理論)最被實驗觀測所支持。 其次,借助于暗能量狀態(tài)方程參數(shù)化的理論,我們利用觀測數(shù)據(jù)討論了宇宙膨脹加速度的演化,發(fā)現(xiàn)宇宙加速度有可能在過去的某時刻開始減小,甚至我們今天的宇宙已經(jīng)進入了減速膨脹的階段。但這些結(jié)果一定程度上依賴于狀態(tài)方程的參數(shù)化形式和觀測數(shù)據(jù)的選擇。 最后,我們用來自于超新星和星系團的觀測數(shù)據(jù),對宇宙學(xué)中聯(lián)系兩種重要距離的關(guān)系距離對偶關(guān)系,進行了不依賴宇宙學(xué)模型的檢測,發(fā)現(xiàn)這個關(guān)系在實際觀測中存在一定程度的偏離,且星系團樣本的選擇和X-射線的Chandra校準(zhǔn)方法對檢測結(jié)果有一定的影響。除此之外,我們利用距離對偶關(guān)系討論了宇宙不透明度,發(fā)現(xiàn)現(xiàn)今觀測還是支持一個完全透明的宇宙,并且支持宇宙學(xué)常數(shù)A0的情況。
[Abstract]:In the past 10-20 years, from a cosmological observation data are very eager to discipline has gradually become a rely on data to promote the development of the subject. For many of the key parameters (e.g., density fraction Omega m, 0, the expansion of the universe reduction factor Q0) the measurement accuracy can be controlled within 10%. Before 1998, people always think that the rate of expansion of the universe is reduced, amazing is that observations of type Ia supernovae but the results indicate that the present universe is experiencing an accelerated expansion process. This observation is based on the fact that people in the universe, there is a strong negative pressure can produce the material energy group the points, namely dark energy, and the total energy of the universe matter accounted for about 2/3. Understanding the nature of dark energy is one of the biggest challenges facing modern physics. In order to avoid the singular understanding of dark energy The challenges brought by the characteristics suggest that the existing Einstein's gravitational theory may no longer be established at the scale of the universe, but that it needs to be properly corrected. These theories can explain the accelerating expansion of the universe without introducing dark energy.
So far, a large number of cosmological model is established. At the same time, the sample data obtained by different astronomical observations more and more big, the accuracy is higher and higher. These data will help us to uncover the mystery of dark energy, or provide a strong basis for understanding the large-scale the law of gravity. Because of this, it is very necessary to observations the theoretical model and experiments together. The first part of this paper discusses the cosmological model of some of the mainstream of the latest observation data limitations. We found that the vacuum energy model (ACDM) is the most observed (type SNLS3la supernova, the cosmic microwave background radiation and baryon acoustic oscillation data, and Harbert data) the support of the candidates. However, when considering only the type SNLS3la supernova data, DGP (membrane theory world) is the most supported by experimental observations.
Secondly, with the help of the dark energy equation of state parameter theory, we use the observational data is discussed. The evolution of cosmic acceleration, acceleration may find the universe at some point in the past began to decrease, even today the universe has entered the decelerating stage. But these results must depend on the equation of state parameter the form and data selection.
Finally, we used data from supernovae and galaxy clusters, the relationship between distance duality between the cosmology of two important contact distance, detect does not depend on the cosmological model, found the relationship between a certain degree of deviation in the actual observations, and cluster sample selection and calibration method of X- ray Chandra have a certain influence on the test results. In addition, we use the distance duality relation discussed universe opacity, finds that the present observation still support a completely transparent universe, and supports the cosmological constant A0 situation.

【學(xué)位授予單位】：湖南師范大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2012
【分類號】：P159

【參考文獻】

相關(guān)期刊論文 前1條

1 ;Testing the distance-duality relation with data from galaxy clusters and type Ia supernovae[J];Research in Astronomy and Astrophysics;2011年08期

，

本文編號：1547532