Dark-Disk Universe

摘要: We point out that current constraints on dark matter imply only the majority of is cold and collisionless. A subdominant fraction could have much stronger interactions. In particular, it interact in a manner dissipates energy, thereby cooling into rotationally supported disk, as baryons do. call this proposed new component double-disk (DDDM). argue DDDM constitute all roughly large baryons, be detected through its gravitational effects motion stars galaxies, for example. Furthermore, if can annihilate to gamma rays, would give rise an indirect detection signal distributed across sky differs dramatically from predicted ordinary matter. more general partially interacting scenarios provide unexplored space testable physics ideas.