The Void Phenomenon Revisited

通过修改初始功率谱解决“大而不能倒”问题和空洞现象

Addressing the too-big-to-fail problem and the void phenomenon through a modified initial power spectrum

本文在偏移集理论框架下，提出在初始曲率功率谱小尺度添加高斯凸起，改变晕丰度与并合频率，以解决缺失卫星、TBTF问题和空洞现象。

Cosmic voids are emptier in the presence of symmetron's domain walls

The symmetron field has an environment (density) dependent behavior which is a common feature of the models with the screening mechanism and results in a rich phenomenology. This model can produce domain walls between regions with different densities. We consider this aspect and study the physics of domain walls in between (underdensity) voids and (overdensity) halo structures. The (spherical) domain walls exert a repulsive force on a test mass outside of the wall while a test mass inside of the wall sees no force. This makes the structures outside the voids go further to a larger radius. Effe…

Dark Matter Halos and Evolution of Bars in Disk Galaxies: Collisionless Models Revisited

We construct and evolve families of steady-state models of stellar disks embedded in live DM halos, in order to study the dynamical and secular phases of bar evolution. These models are tested against those published in the literature in order to extend them and include the gaseous component in the follow up paper. We are interested in the angular momentum (J) redistribution in the disk-halo system. We confirm the previous results and quantify for the first time the dual role that the DM halos play in the bar evolution: more centrally concentrated halos dilute the dynamical processes, such as …