Cosmological Modified Gravity Simulations with Massive Sterile Neutrinos

该项目将涉及建立一个大型的（>100 Mpc）修正重力（MOND）框架中的宇宙学模拟，但补充了11 eV的不育中微子，以构成与LCDM宇宙学相同的总暗能量和物质密度。模拟将建立在现有的不育中微子+ MOND框架的模拟基础上（例如Katz+ 2013），获得了有希望的结果。该项目将使用现有的Phantom of RAMSES代码（Nagesh+ 2021），在修正的重力下结合牛顿初始条件，红移约为200，MOND效应应该可以忽略不计。在大尺度上，结构的形成将比LCDM更快，而在小尺度上，冷暗物质的缺乏将被增强的长程引力定律所补偿，其目的是寻找（1）类似于El Gordo的大质量星系团对和（2）类似于当地300 Mpc的KBC空洞;这两个都排除了高于6 σ显著性的LCDM（Haslbauer+ 2020，Asencio+ 2021）。更一般地说，模拟结果将与一系列观察结果进行比较，例如，在低密度区域（空洞）中，像我们这样的观测者在500 Mpc范围内的星系团质量函数。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，该小组长期以来一直对类似问题感兴趣，并有研究人员在类似领域工作。参见Banik和Zhao最近的评论（https：//arxiv.org/abs/2110.06936）和最近的一个关于修正重力的邀请讲座，参见（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).