报告题目：Ultra-Light Axion Dark Matter and its impacts on dark halo structure in N-body simulation
时 间：11月15日（周二）下午 14:00
报告摘要: The Ultra-Light Axion (ULA) is a dark matter candidate with mass O(1e-22) eV and its de Broglie wavelength is of order kpc. Such an axion, also called the Fuzzy Dark Matter (FDM), thermalizes via the gravitational force and forms a Bose-Einstein condensate. Recent studies suggested that the quantum pressure from the FDM can significantly affect the structure formation in the small scale, thus alleviating the so-called "small-scale crisis". In this paper, we develop a new technique to discretize the quantum pressure and illustrate the interactions among the FDM particles in the NN-body simulation, which accurately simulates the formation of the dark-matter halo and its inner structure. In a self-gravitationally-bound virialized halo, we find a constant density core, called solitonic core, with size of around 1 kpc, which is consistent with the theoretical prediction. The density distribution outside the core follows a normal CDM prediction described by the Einasto profile. However, the core density is higher than the normal CDM density, which reveals the non-linear effect of quantum pressure and impacts the structure formation in the FDM model.
报告人简介：蔡岳霖博士于新竹国立交通大学物理所硕士期间(2002-2004)钻研“太阳中微子振荡”, 之后于英国谢菲尔德 (天文与物理系)博士毕业(2006-2011)，论文题目为“超对称暗物质搜寻”，并且2006-2007于意大利SISSA进修。毕业后在波兰国家核子研究中心担任青年科学家(2011-2013)，以及东京大学-卡弗里-数物连携宇宙研究机构担任博士后研究员 （2013-2016）。