Cosmological Modified Gravity Simulations with Massive Sterile Neutrinos

该项目将包括在修正引力(MOND)框架下建立一个大型(100MPC)宇宙学模拟，但补充11 eV的稀有中微子，以组成与Lambda冷暗物质(LCDM)宇宙学中相同的总暗能量和物质密度。模拟将建立在现有的稀薄中微子+MOND框架(例如Katz+2013)模拟的基础上，获得了令人振奋的结果。该项目将使用现有的Ramses幻影代码(Nagesh+2021)，在红移约为200的情况下，结合修正引力和牛顿初始条件，此时MOND效应应可忽略不计。在大尺度上，结构形成将比LCDM进行得更快，而在小尺度上，冷暗物质的缺乏将被增强的长期引力定律所补偿。目标是寻找(1)类似El Gordo的大质量星系团对和(2)本地300Mpc KBC空洞的类似物；这两者都排除了LCDM超过6西格玛意义(Haslbauer+2020，Asencio+2021)。更广泛地说，模拟的结果将与一系列观测结果进行比较，例如像我们这样的低密度区域(空洞)的观测者在500 Mpc内的星团质量函数。该项目将由赵洪生博士监督，并由Indranil Banik博士密切指导。它将与波恩的动力学小组合作，后者长期以来一直对类似的问题感兴趣，研究人员也在类似的领域工作。请参阅Banik&赵最近的一篇评论(https://arxiv.org/abs/2110.06936)和最近一次关于修改重力的特邀讲座，请参阅(https://www.youtube.com/watch?v=jL09gRe1q7s).

This project would involve setting up a large (>100 Mpc) cosmological simulation in the Modified Gravity (MOND) framework, but supplemented with 11-eV sterile neutrinos to make up the same total dark energy and matter density as in the Lambda Cold Dark Matter (LCDM) cosmology.The simulations would build on existing simulations of the sterile neutrino + MOND framework (e.g. Katz+ 2013) that obtained promising results. The project would use the existing Phantom of RAMSES code (Nagesh+ 2021) in Modified Gravity combined with Newtonian initial conditions at a redshift of about 200, when MOND effects should be negligible. Structure formation would proceed more rapidly than in LCDM on large scales, while on small scales the lack of cold dark matter would be compensated by an enhanced long range gravity law.The aim would be to look for (1) analogues to the El Gordo-like massive galaxy cluster pair and (2) analogues to the local 300 Mpc KBC void; both of these rule out LCDM above 6-sigma significance (Haslbauer+ 2020, Asencio+ 2021). More generally, the results of the simulations would be compared with a range of observations, e.g., the cluster mass function within 500 Mpc of observers like us in a low-density region (void).The project would be supervised by Dr Hongsheng Zhao and closely guided by Dr Indranil Banik. It would be in collaboration with the dynamics group in Bonn, which has long been interested in similar problems and has researchers working on a similar area. See a recent review by Banik & Zhao (https://arxiv.org/abs/2110.06936) and a recent invited lecture overviewing Modified Gravity, see (https://www.youtube.com/watch?v=jL09gRe1q7s).