Confrontation of Cosmological Models with Observations

PI正在使用自适应细化树（ART）代码来解决宇宙学中的两个问题：(1)暗物质晕的结构、动力学和空间分布；(2)不同宇宙学模型中星系形成的物理学。暗物质晕代表了宇宙学模型之间的中间但非常重要的联系，宇宙学模型处理宇宙的全局参数和观测（例如，星系的功率谱，星系速度的不同统计数据，暗物质主导星系的旋转速度）。理论预测是不确定和不一致的。关于中心部分的剖面（尖头的坡度）没有一致的意见。PI正在进行广泛的模拟，以解决问题并产生有关暗物质晕的结构和分布的可靠结果。关于星系形成的理论预测仍处于初级阶段。PI正在使用现实的n体+水力模拟来测试不同的物理机制和假设，以减少这些不确定性。主要从事恒星形成反馈、亚分辨率物理、多相介质和金属富集等效应的研究。＊＊＊

AST 98-02787 Anatoly A. Klypin The PI is using the Adaptive Refinement Tree (ART) code to address two problems in cosmology: (1) the structure, dynamics and spatial distribution of dark matter halos, and (2) the physics of galaxy formation in different cosmological models. The dark matter halos represent intermediate, but very important link between cosmological models, which deal with global parameters of the Universe and observations (e.g., power spectra of galaxies, different statistics of velocities of galaxies, rotational velocities of dark matter dominated galaxies). Theoretical predictions are uncertain and inconsistent. There is no consensus regarding projiles in the central parts (slope of the cusps). The PI is carrying out extensive simulations that will resolve the issues and produce reliable results concerning structure and distribution of dark matter halos. Theoretical predictions of formation of galaxies are still in their infant stage. The PI is using realistic n-body + hydro simulations to test different physical mechanisms and assumptions in order to reduce those uncertainties. He is studying such effects as the star formation feedback, the subresolution physics, the multiphase medium and the metal enrichment. ***