The one thing is that the dark matter particles seems not to interect with each other so as to form a body and other thing is that they clump togather .It means that there are some neutral particals also that interect between some big dark matter particals i.e. they break from one big particle and joined other big particle so that clumping occur.The big particles may be neutron like particles.We can not detect them as they may be in wave form.
What is the effect of light on this dark matter compared with black hole.
