本文選題：暗能量 + 正壓背景流體�。� 參考：《遼寧師范大學(xué)》2011年碩士論文

【摘要】：隨著對Ia超新星、宇宙做波背景輻射以及大尺度結(jié)構(gòu)等的觀測表明當(dāng)前宇宙正處于加速膨脹狀態(tài)。天文觀測還表明宇宙中各組分的比例大致為：73％的暗能量，23％的暗物質(zhì)和4％的重子物質(zhì)。暗能量所占比例很大，是當(dāng)前宇宙的重要組成部分。為了更加科學(xué)的研究宇宙，，幾們建立了大量的宇宙學(xué)模型，最簡單的暗能量模型是宇宙學(xué)常數(shù)。常見的暗能量模型還有：Quitessence，Phantom，Tachyon，K-essence，全息暗能量，Chaplygin氣體(CG)及其推廣模型等。 對于CG及它的推廣模型，其最吸引幾的性質(zhì)在于能將宇宙中兩個不可見的暗部分(即暗物質(zhì)和暗能量)巧妙地統(tǒng)一起來。其中研究最廣泛的是廣義Chaplygin氣體(GCG)模型。新的廣義Chaplygin氣體(NGCG)模型作為GCG模型的推廣也被建立。該模型包含了暗能量態(tài)參數(shù)為常數(shù)的情行，其早期行為類似于暗物質(zhì)，而晚期類似于宇宙學(xué)常數(shù)。 本文將主要討論NGCG流體與正壓背景流體之間存在相互作用(相互作用項取為Q = 3Hc(ρ_(NGCG)+ρ_γ))時動力學(xué)系統(tǒng)的穩(wěn)定性問題。通過對NGCG模型動力學(xué)自洽系統(tǒng)的討論，得到了該動力學(xué)系統(tǒng)的臨界點，進而求得了該模型的吸引子。進一步，文中描繪了該模型中相關(guān)宇宙學(xué)量的演化，即NGCG流體態(tài)參數(shù)、無量綱密度參數(shù)及聲速的演化。最后，文中對NGCG模型進行了Om幾何診斷，將該模型的Om曲線與ΛCDM的Om曲線做對比，直觀地展示了二者之間的差異。
[Abstract]:With the observation of Ia supernova, cosmic background radiation and large scale structure, it is shown that the universe is in the state of accelerating expansion. Astronomical observations also show that the proportion of components in the universe is approximately: 73% dark energy 23% dark matter and 4% baryon matter. Dark energy accounts for a large proportion and is an important part of the current universe. In order to study the universe more scientifically, many cosmological models have been established, and the simplest dark energy model is cosmological constant. The common dark energy models include: Q Q Phantomo Tachyon K-essence, holographic dark energy Chaplygin gas (CGG) and its generalized model. Its most attractive nature is the ability to neatly unify two invisible dark parts of the universe, namely dark matter and dark energy. The generalized Chaplygin gas GCGmodel is the most widely studied. A new generalized Chaplygin gas NGCGG model is also established as a generalization of the GCG model. The model contains constant dark energy state parameters and its early behavior is similar to that of dark matter. In this paper, we mainly discuss the stability of the dynamical system when the interaction between NGCG fluid and barotropic background fluid is Q = 3Hc (蟻 _ S / NGCG蟻 _ 緯). By discussing the dynamical self-consistent system of NGCG model, the critical point of the dynamic system is obtained, and the attractor of the model is obtained. Furthermore, the evolution of the relevant cosmological quantities in the model, namely, the evolution of NGCG flow state parameters, dimensionless density parameters and sound velocity, is described in this paper. Finally, the Om geometric diagnosis of NGCG model is carried out, and the Om curve of this model is compared with that of A CDM, and the difference between them is shown intuitively.
【學(xué)位授予單位】：遼寧師范大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2011
【分類號】：P159

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相關(guān)期刊論文 前1條

1 ;Modified Chaplygin gas as an interacting holographic dark energy model[J];Science China(Physics,Mechanics & Astronomy);2010年04期

相關(guān)碩士學(xué)位論文 前1條

1 付歡歡;廣義CG氣體模型的動力學(xué)穩(wěn)定性及其相互作用性質(zhì)的研究[D];遼寧師范大學(xué);2009年

本文編號：1996612