Over a handful of rotation periods, dynamical processes in barred galaxies induce non-axisymmetric structure in dark matter halos. Using n-body simulations of a Milky Way-like barred galaxy, we identify both a trapped dark-matter component, a shadow bar, and a strong response wake in the dark-matter distribution that affects the predicted dark-matter detection rates for current experiments. The presence of a baryonic disk together with well-known dynamical processes (e.g. spiral structure and bar instabilities) increase the dark matter density in the disk plane. We find that the magnitude of the combined stellar and shadow bar evolution, when isolated from the effect of the axisymmetric gravitational potential of the disk, accounts for >30% of this overall increase in disk-plane density. This is significantly larger that of previously claimed deviations from the standard halo model. The dark-matter density and kinematic wakes driven by the Milky Way bar increase the detectability of dark matter overall, especially for the experiments with higher $v_{min}$. These astrophysical features increase the detection rate by more than a factor of two when compared to the standard halo model and by a factor of ten for experiments with high minimum recoil energy thresholds. These same features increase (decrease) the annual modulation for low (high) minimum recoil energy experiments. We present physical arguments for why these dynamics are generic for barred galaxies such as the Milky Way rather than contingent on a specific galaxy model.
Modified Dark Matter in Galaxies and Galaxy Clusters
修正的暗物质（Modified Dark Matter，MDM）是一个受引力热力学启发的暗物质唯象模型，它自然地解释了在银河系自转曲线数据中观察到的宇宙加速常数;与宇宙学常数$Λ$相关的临界加速度是MDM的唯象表现。我们表明，由此产生的质量配置文件，这是敏感的$Λ$，是一致的，在银河系和星系团尺度的观测。我们的研究结果表明，暗物质质量分布包含的信息，宇宙学常数在一个非平凡的方式。
The non-gravitational interactions of dark matter in colliding galaxy clusters
星系团之间的碰撞提供了对作用于暗物质的非引力的测试。暗物质在“子弹团碰撞”中没有减速，这限制了它在长程作用力下的自相互作用截面σ_DM/m <1.25 cm 2/g（68%置信限）。利用钱德拉和哈勃太空望远镜，我们现在已经观测到72次碰撞，包括“大”和“小”合并。结合这些测量统计，我们检测到暗质量的存在在7.6σ的显着性。暗物质的位置在5.8+/-8.2 kpc的关联恒星范围内保持紧密排列：这意味着自相互作用截面σ_DM/m < 0.47 cm 2/g（95% CL），并且不利于对标准模型的一些建议扩展。
Dark Matter and Galaxy Cross-Correlations with the Cherenkov Telescope Array Observatory
Flatiron Institute（平顿研究所）；Perimeter Institute for Theoretical Physics（理论物理前沿研究所）；Fermi National Accelerator Laboratory（费米国家加速器实验室）；University of Chicago, Kavli Institute for Cosmological Physics（芝加哥大学卡弗里宇宙物理学研究所）；University of Nova Gorica, Center for Astrophysics and Cosmology（新戈里察大学天体物理学与宇宙学中心）；Instituto de Física Corpuscular (IFIC), University of Valencia and CSIC（瓦伦西亚大学及西班牙高等科研理事会粒子物理研究所（IFIC））；Dipartimento di Fisica, Università degli Studi di Torino（都灵大学物理系）；INFN – Istituto Nazionale di Fisica Nucleare, Sezione di Torino（意大利国家核物理研究所都灵分部）；INAF – Istituto Nazionale di Astrofisica, Osservatorio Astrofisico di Torino（意大利国家天体物理都灵天文台）
