-dark atoms-

For people who don't follow these postulates closely it probably seems there is a lot of energy put in to illustrate in the worlds of physics and nature the pursuit of invisible natures, especially those often depicted as "dark". Recent years see a lot of time and effort to delineate on these natures. They are portrayed as being found or likely found here and there in the universe.

Scientists hone in on those natures which are a challenge to bring forth to knowledge to give credible establishment because of the features of the objects being pursued do not show up visibly. 

Many postulates have come forth in the last 40 years, some have been mind boggling even to disciplined scientists.  They also try to find a common denominator to the dark realm, at times termed 'dark sector', by which to better track these presences. There is one effort to get a substrate to the dark realm now, a hypothesis of dark atoms. Certainly, if dark atoms are sustained in evidence, then like the ordinary. baryon atom, these could be pervasive in the universe This is held to come from features of a pervasive nature which comprises 80+% of known matter termed 'dark matter'.

It has been studied a lot in recent decades for details and pervasiveness. As of yet there has not been a distinct element which could be the dark matter, but the attributed nature is so compellingly evident in the universe. [Keep in mind that this dark matter is considered matter, material. As a material, it could kill someone like other matter encounters happen. It is less likely on this planet as there is not much evidence of dark matter being mixed with our planet. Yet, a least one paper by scientists was dedicated to the lethal possibility of the presence of dark matter.] 

The authors say, the dark sectors  frequently include a fraction of dark matter with dissipative self-interactions, which can cool and clump in opposition to the purely gravitational dynamics of  cold dark matter. This includes the annihilation phase of dark matter which produces various  residue. From this can be derived the tag Atomic Dark Matter (ADM); which consists of of a dark proton, dark electrons that interact through a massless dark photon with coupling. "The ADM can form a dark hydrogen bound-state and radiatively cools in direct analogy to the Standard Model."

The universe is cold. The gases are cold, And there is cold dark matter. This is said by the authors to have influence on distribution of bodies in the cosmos as in contrast with heated sources which produce a different process in a different way.

"They have found that atomic dark matter can very rapidly clump up, forming a 'shadow disk'...From there the dark atoms continue to clump, forming the equivalent of dark stars and black holes. It can even quickly sink into the core of the galaxy, rapidly increasing the density there." The dark matter elements clumping can clump together very tightly. And this would happen invisibly. This could result in a difference in the process of evolution of clumping, as in a hydrodynamical process in the Milky Way.

A paper on atomic dark matter may be found: arxiv.org 2304.09878

A related paper can be garnered, arxiv.org: 2209.00064