New tests of physics with constrained large-scale structure simulations

星系形成的典型模拟对原始密度扰动采用随机相位，因此产生具有特定统计属性但在空间中的任意位置的结构。相反，“受约束的”模拟与实际局部宇宙的物质分布相匹配，允许模拟中的对象与观测到的星系和结构之间的一对一映射。该学生将利用一套名为CsiBORG的受限N-Body模拟(Bartlett等人。2021年)设计和开展天体物理模型的新研究。这可能包括测试半解析星系形成模型，寻找暗物质和可见光物质随宇宙时间演化之间的关系，开发或利用一种识别局部宇宙中空洞的新方法(Desmond等人)。2022年)，和/或量化由于附近结构而在局部测量的宇宙膨胀率中的潜在偏差。学生还可以运行他们自己的受限模拟，例如通过添加流体动力学和辐射转移来探索局部宇宙的电离历史，和/或约束中性/分子氢在局部宇宙中的分布。

Typical simulations of galaxy formation adopt random phases for the primordial density perturbations and therefore produce structures with specified statistical properties but arbitrary positions in space. In contrast, "constrained" simulations match the matter distribution of the actual local Universe, allowing a one-to-one mapping between objects in the simulation and observed galaxies and structures. The student will leverage a suite of constrained N-body simulations called CsiBORG (Bartlett et al. 2021) to devise and carry out novel investigations of astrophysical models. This may include testing semi-analytic galaxy formation models, searching for correlations between the evolution of dark matter and visible matter over cosmic time, developing or exploiting a new method for identifying voids in the local Universe (Desmond et al. 2022), and/or quantifying potential bias in the locally measured expansion rate of the Universe due to nearby structure. There is also scope for the student to run their own constrained simulations, for example with the addition of hydrodynamics and radiative transfer to explore the reionization history of the local Universe, and/or to constrain the distribution of neutral/molecular hydrogen in the local Universe.