芝加哥大学天文学科研项目

University of Chicago Astronomical Research Program

科研主题

以下领域内的相关课题，具体课题根据学生的基础，导师面试后确定。

Cosmology physics［宇宙物理学］

Theoretical Astrophysics［理论天体物理学］

Cosmology and elementary particle physics［宇宙学和基本粒⼦物理学］

cosmology［宇宙学］

Dark energy［暗能量］

Dark substance［暗物质］

Development of detector［探测器研制］

Computational cosmology［计算宇宙学］

科研内容（参考课题）

Testing Modified Gravity with Cosmic Microwave Background

Keywords: Cosmic Microwave Background, MCMC, Modified Gravity

Candidates: Students who are interested in cosmology / cosmic microwave background (CMB) and modified gravity. Students should have fair physics background (basic knowledge about classical mechanics, thermal physics, electromagnetic dynamics and quantum physics, better if were familiar with General Relativity). Students should have basic programming skills (at least be familiar with one programming language, better if were familiar with python and fortran).

Introduction: Although LCDM model has achieved a big success in fitting observational data, the nature of dark energy still remains unknown. The most simple description of dark energy – a cosmological constant – has its own theoretical difficult and observational tension. This motivated people to continue seeking explanations to the accelerated expansion other than the simple cosmological constant, and modified gravity is such an alternative. Testing modified gravity has become one of the central focuses in modern cosmology. We are going to carry the tests by implementing modified gravity into the Boltzmann code and comparing the results to the observational datasets.

Specifically, this project is more programming-oriented. We are going to learn the basic physics of CMB and how to constrain cosmological parameters via Markov Chain Monte Carlo (MCMC) method. Beyond that we are going to modified the cosmology model by implementing modified gravity models, and try to test such models with cosmological observation datasets. The rate of progress could be adjusted according to actual conditions.

References:

1.      Hojjati et al. “Testing gravity with CAMB and CosmoMC” J. Cosmology Astropart. Phys. 8, 005 (2011), arXiv:1106.4543

2.      Zhao et al. “Searching for modified growth patterns with tomographic surveys” Phys. Rev. D 79, 083513 (2009), arXiv:0809.3791