我們專注於可行f(R)重力理論的分支，Tsujikawa模型的宇宙學特性，其中包括宇宙背景演化與線性微擾理論。利用CosmoMC的軟體，我們得到了宇宙學參數的限制，並證明了Tsujikawa 模型下的宇宙，微中子總質量的限制範圍會被放寬，如同其他的f(R)重力模型。另外，我們也討論了狀態方程式與減速參數的演化並與 ΛCDM 模型做比較。

We concentrate on the cosmological properties in the Tsujikawa model (TM) of viable f(R) gravity with the dynamical background evolution and linear perturbation theory by using the CosmoMC package. We study the constraints of the cosmological variables along with the model parameter from the current observational data. In particular, we show that the matter density fluctuation is enhanced and the constraint of the neutrino mass sum is relaxed in the TM, which are similar to other viable f(R) models. In addition, we discuss the parameters of the deceleration and equation of state for dark energy in the TM and compare them with those in the ΛCDM model.

Abstract
Acknowledgements
Contents ----- i
Lists of Tables ----- ii
Lists of Figures ----- iii
1. Introduction ----- 1
2. Tsujikawa model of viable f(R) gravity ----- 4
3. Cosmological evolutions in Tsujikawa model ----- 9
4. Constraints on Tsujikawa Model from Cosmological Observations ----- 28
5. Conclusions ----- 39
Reference ----- 41

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